Fixes #12795

It was already possible to create domain blocks for TLDs, but those
weren't enforced, nor editable. This commit changes it so that they
are enforced and editable.

Move public domain blocks information to about page

* Add automatic blocklist display in /about/blocks

Inspired by https://github.com/Gargron/mastodon.social-misc

* Add admin option to set who can see instance blocks

* Normalize locales files

* Rename “Sandbox” to “Silence” for consistency

* Disable /about/blocks when in whitelist mode

* Optionally display rationale for domain blocks

* Only display domain blocks that have user-facing limitations, and order them

* Redesign table of blocked domains to better handle long domain names and rationales

* Change domain blocks ordering now that rationales aren't displayed right away

* Only show explanation for block severities actually in use

* Reword instance block explanations and add disclaimer for public fetch mode

Fix #7629

* Add database columns for adding notes to domain blocks/restrctions

* Add admin UI to set private and public comments when blocking a domain

* Add text for private and public comments on domain blocks

* Show domain block comments in admin UI

* Add comments to the domain block undo page

* Make UnblockDomainService more robust regarding upgraded domain blocks

* Allow editing domain blocks

* Rename button from “undo domain block” to “view domain block” in account admin UI

* Change test to unsilence silenced users from upgraded blocks

* Change domain blocks to automatically support subdomains

If a more authoritative domain is blocked (example.com), then the
same block will be applied to a subdomain (foo.example.com)

* Match subdomains of existing accounts when blocking/unblocking domains

* Improve code style

* Record account suspend/silence time and keep track of domain blocks

* Also unblock users who were suspended/silenced before dates were recorded

* Add tests

* Keep track of suspending date for users suspended through the CLI

* Show accurate number of accounts that would be affected by unsuspending an instance

* Change migration to set silenced_at and suspended_at

* Revert "Also unblock users who were suspended/silenced before dates were recorded"

This reverts commit a015c65d2d.

* Switch from using suspended and silenced to suspended_at and silenced_at

* Add post-deployment migration script to remove `suspended` and `silenced` columns

* Use Account#silence! and Account#suspend! instead of updating the underlying property

* Add silenced_at and suspended_at migration to post-migration

* Change account fabricator to translate suspended and silenced attributes

* Minor fixes

* Make unblocking domains always retroactive

* When trying to block an already-blocked domain, provide a link to the block

* Fix styling for links in flash messages

* Allow blocks to be upgraded but not downgraded

* Update annotate to version 2.7.3

* Update aws-sdk-s3 to version 1.9.2

* Update browser to version 2.5.3

* Update capistrano to version 3.10.2

* Update domain_name to version 0.5.20180417

* Update http to version 3.2.0

* Update lograge to version 0.10.0

* Update oj to version 3.5.1

* Update parallel_tests to version 2.21.3

* Update puma to version 3.11.4

* Update rubocop to version 0.55.0

* Update scss_lint to version 0.57.0

* Update simplecov to version 0.16.1

* Update tty-command to version 0.8.0

* Update tty-prompt to version 0.16.0

* Update pkg-config to version 1.3.0

* Update fog-local to version 0.5.0

* Update fog-openstack to version 0.1.25

* Update devise-two-factor to version 3.0.3

* bundle update

* Add structure for lists

* Add list timeline streaming API

* Add list APIs, bind list-account relation to follow relation

* Add API for adding/removing accounts from lists

* Add pagination to lists API

* Add pagination to list accounts API

* Adjust scopes for new APIs

- Creating and modifying lists merely requires "write" scope
- Fetching information about lists merely requires "read" scope

* Add test for wrong user context on list timeline

* Clean up tests

All the migrations have been updated to use BIGINTs for ID fields in the DB, but ActiveRecord needs to be told to treat those values as BIGINT as well. This PR does that.

* Make IdsToBigints (mostly!) non-blocking

This pulls in GitLab's MigrationHelpers, which include code to make
column changes in ways that Postgres can do without locking. In general,
this involves creating a new column, adding an index and any foreign
keys as appropriate, adding a trigger to keep it populated alongside
the old column, and then progressively copying data over to the new
column, before removing the old column and replacing it with the new
one.

A few changes to GitLab's MigrationHelpers were necessary:

* Some changes were made to remove dependencies on other GitLab code.
* We explicitly wait for index creation before forging ahead on column
  replacements.
* We use different temporary column names, to avoid running into index
  name length limits.
* We rename the generated indices back to what they "should" be after
  replacing columns.
* We rename the generated foreign keys to use the new column names when
  we had to create them. (This allows the migration to be rolled back
  without incident.)

# Big Scary Warning

There are two things here that may trip up large instances:

1. The change for tables' "id" columns is not concurrent. In
   particular, the stream_entries table may be big, and does not
   concurrently migrate its id column. (On the other hand, x_id type
   columns are all concurrent.)
2. This migration will take a long time to run, *but it should not
   lock tables during that time* (with the exception of the "id"
   columns as described above). That means this should probably be run
   in `screen` or some other session that can be run for a long time.
   Notably, the migration will take *longer* than it would without
   these changes, but the website will still be responsive during that
   time.

These changes were tested on a relatively large statuses table (256k
entries), and the service remained responsive during the migration.
Migrations both forward and backward were tested.

* Rubocop fixes

* MigrationHelpers: Support ID columns in some cases

This doesn't work in cases where the ID column is referred to as a
foreign key by another table.

* MigrationHelpers: support foreign keys for ID cols

Note that this does not yet support foreign keys on non-primary-key
columns, but Mastodon also doesn't yet have any that we've needed to
migrate.

This means we can perform fully "concurrent" migrations to change ID
column types, and the IdsToBigints migration can happen with effectively
no downtime. (A few operations require a transaction, such as renaming
columns or deleting them, but these transactions should not block for
noticeable amounts of time.)

The algorithm for generating foreign key names has changed with this,
and therefore all of those changed in schema.rb.

* Provide status, allow for interruptions

The MigrationHelpers now allow restarting the rename of a column if it
was interrupted, by removing the old "new column" and re-starting the
process.

Along with this, they now provide status updates on the changes which
are happening, as well as indications about when the changes can be
safely interrupted (when there are at least 10 seconds estimated to be
left before copying data is complete).

The IdsToBigints migration now also sorts the columns it migrates by
size, starting with the largest tables. This should provide
administrators a worst-case scenario estimate for the length of
migrations: each successive change will get faster, giving admins a
chance to abort early on if they need to run the migration later. The
idea is that this does not force them to try to time interruptions
between smaller migrations.

* Fix column sorting in IdsToBigints

Not a significant change, but it impacts the order of columns in the
database and db/schema.rb.

* Actually pause before IdsToBigints

* Allow domain blocks to reject media without silencing or suspending

* Fix typo

* Hide 'Reject media' button when superfluous, instead of disabling it

* Properly hide 'reject media' checkbox on page load if needed

This may happen when resubmitting the domain block form after an error.

* Don't ask whether undoing a media-only block should be retroactive

* Rename :media_only block to :noop

* Display :noop block as None in frontend, allow blocks that do nothing

* Remove 'coding' line auto-added by emacs

* Fix boolean columns sometimes having a null value

* Fix wrong value being set instead of null

* add annotate to Gemfile

* rails g annotate:install

* configure annotate_models

* add schema info to models

* fix rubocop to add frozen_string_literal

* Fix #2119 - Whenever about to send a HTTP request, normalize the URI

* Add test for IDN request in FetchLinkCardService

* Perform IDN normalization on domains before they are stored in the DB

* Rename admin.domain_block to admin.domain_blocks in prep for i18n improvement

* Use implicit controller/action path for i18n in admin/domain_blocks

* Add DomainBlock#accounts has_many

* Avoid i18n health warning for `en` locale by using symbol scope with :count

* Remove unused i18n key: plaintext_secret_html

* Remove unused i18n key two_factor_auth.warning

* Remove final will_paginate i18n keys

* Remove unused key two_factor_auth.recovery_codes

* Remove unused key: admin.reports.comment.none

* Remove unused reports. i18n namespace (moved to admin.reports)

* Ignore keys from locales which override activemodel and activerecord errors

* Revert "Remove unused key: admin.reports.comment.none"

This reverts commit 350ef2685f.

* Update i18n key reference to match moved location

* Add missing `en` keys to i18n

* Tell i18n-tasks to ignore missing attributes that dont need overwriting

* Add i18n-tasks unused to travis

Create MediaAttachment but without actual file download when domain is blocked with reject_media set to true
Clean up old media files when creating a new domain block with reject_media set to true
Return remote_url in media attachments API if local file is not present
Undo domain block action in admin UI
Ability to enable reject_media from admin UI

"whole known network" which is what public timeline used to be

Only domain blocks with suspend severity will block PuSH subscriptions
Silenced accounts should not appear in conversations unless followed