Fix #2350

Fixes #9045

* Add silent column to mentions

* Save silent mentions in ActivityPub Create handler and optimize it

Move networking calls out of the database transaction

* Add "limited" visibility level masked as "private" in the API

Unlike DMs, limited statuses are pushed into home feeds. The access
control rules between direct and limited statuses is almost the same,
except for counter and conversation logic

* Ensure silent column is non-null, add spec

* Ensure filters don't check silent mentions for blocks/mutes

As those are "this person is also allowed to see" rather than "this
person is involved", therefore does not warrant filtering

* Clean up code

* Use Status#active_mentions to limit returned mentions

* Fix code style issues

* Use Status#active_mentions in Notification

And remove stream_entry eager-loading from Notification

Fix #8685

* Revert "Fix some icon names changed by the Font Awesome 5. (#8796)"

This reverts commit 3f9ec3de82.

* Revert "Migrate to font-awesome 5.0. (#8799)"

This reverts commit 8bae14591b.

* Revert "Fix some icons names, unavailable in fontawesome5 (free license). (#8792)"

This reverts commit b9c727a945.

* Revert "Update the icon name changed by the Font Awesome 5. (#8776)"

This reverts commit 17af4d27da.

* Revert "Add bot icon to bot avatars and migrate to newer version of Font Awesome (#8484)"

This reverts commit 4b794e134d.

Add tests to avoid similar issues in the future

* Add animate custom emoji param to embed pages

* Rename param, use it for avatars and gifs

* Fix issues pointed by codeclimate and breaking test

* Ignore brakeman warning

* Pass through video description as necessary.

* Add title to video, matching aria-label.

* Add remote interaction dialog for toots

* Change AuthorizeFollow into AuthorizeInteraction, support statuses

* Update brakeman.ignore

* Adjust how interaction buttons are display on public pages

* Fix tests

* Add follow button to detailed status, add gradient to mask bio cut-off

* In landing strip, show sign up link even if closed (different href)

Point to joinmastodon.org

Fix #7926

* Make embeds cacheable by reverse proxy

* Make follow button on embeds open remote follow modal

Instead of web+mastodon://, also, turn the button blue, and add a
sign up prompt to the remote follow modal

Follow-up to #6124

* Fix URL of "Show more" link in paginated threads (ancestors side)

Increase item limits in threads

Fix #7268

* Fix "Show more" link in paginated threads (descendants side)

* Use table for statuses in report

* Display reported account and reporter in the same table

* Split accounts and general report info into two tables again

* Redesign report statuses table, notes, merge notes and action log

* Remove unused translations

* Fix code style issue

* Fix code style issue

* Fix code style issue

This also limits the statuses returned by API, but pagination is not
implemented in Web API yet. I still expect it brings user experience
better than making a user wait to fetch all ancestor statuses and flooding
the column with them.

Display summary of attachments in description, and mark up content
warning if present, e.g.:

    Attached: 3 images · Content warning: Dota 2

When text is not supposed to be hidden, it looks more like:

    Attached: 3 images

    Here is the text of the toot

With #6817, multilinguagility should be assured...

* Responsively enforce 16:9 ratio on all media thumbnails in web UI

Also change video player behaviour to "contain" rather than
"cover" videos that don't fit the ratio, unlike images and GIFs,
it's expected that a video is shown fully.

* Fix spacing issues and remove floor

* Remove floor

* Save metadata from video attachments, put correct dimensions into OG tags

* Add twitter:player for videos

* Fix code style and test

Reasoning: HTML title tag affects everyone. But OpenGraph only affects
when somebody is deliberately sharing the content, usually in an
environment where such content is expected. Hiding the content in
OpenGraph tags results in deceitful previews which inhibit the
shareability of the post.

Example: Somebody writes a clever post about politics but kindly
puts a "uspol" content warning on it. Mastodon users are thankful,
but sharing this post on another platform results in non-Mastodon
users believing the entire contents of the post is "uspol" and not
clicking through/reading and re-sharing.

* Fix #5082 - disable retweet link for followers only toot

* Hide reblog count when it is a direct message

* Add option to reduce motion

* Use HOC to wrap all Motion calls

* fix case-sensitive issue

* Avoid updating too frequently

* Get rid of unnecessary change to _simple_status.html.haml

* In detail status view, display attachment uncropped if there's only one

* Make media spoiler the size of the media it hides, enable on static

Additionally, this restores previous background / text color for media spoiler.

* Custom emoji

- In OStatus: `<link rel="emoji" name="coolcat" href="http://..." />`
- In ActivityPub: `{ type: "Emoji", name: ":coolcat:", href: "http://..." }`
- In REST API: Status object includes `emojis` array (`shortcode`, `url`)
- Domain blocks with reject media stop emojis
- Emoji file up to 50KB
- Web UI handles custom emojis
- Static pages render custom emojis as `<img />` tags

Side effects:

- Undo #4500 optimization, as I needed to modify it to restore
  shortcode handling in emojify()
- Formatter#plaintext should now make sure stripped out line-breaks
  and paragraphs are replaced with newlines

* Fix emoji at the start not being converted

* Redesign video player

* Use new video player on static public pages too

* Use media gallery component on static public pages too

* Pause video when hiding it

* Full-screen sizing on WebKit

* Add aria labels to video player buttons

* Display link card on public status page

* Fix fullscreen from modal sizing issue

* Remove contain: strict property to fix fullscreen from columns

- Return all images as og:image
- Return videos as og:image (preview) and og:video
- Return profile:username on profiles