Fix #3894

* Add default_settings class method to ScopedSettings

ScopedSettings was extended to use value of unscoped setting instead of
only using defaults set in config/settings.yml for selected settings.
This adds possibility for admins to set default values of users' settings,
for example default theme (as requested in #7092).

* Add ability to change an instance default theme

Closes #7092

* Add confirmation page for suspensions

* Suspension confirmation closes reports, linked from report UI

* Fix tests

* Add separate setting for sidebar text (site_short_description)

* Fix tests

* Add option to show only local toots in timeline preview
Right know, toots from all the known fediverse are shown in the main
page of an instance. That however doesn't reflect the instance itself.
With this option the admin may choose to display only local toots so
that users checking the instance get a better idea of internal
conversations.

* Fix issues pointed by codeclimate and eslint

* Add default message for community timeline

* Update pl.yml

The service used to be named ResolveRemoteAccountService resolves local
accounts as well.

* Add GET /api/v1/instance/peers API to reveal known domains

* Add GET /api/v1/instance/activity API

* Make new APIs disableable, exclude private statuses from activity stats

* Fix code style issue

* Fix week timestamps

* Make removable account migration

* Fix error during update of account migration setting

* Add notice when update account migration setting

* Add consumable invites

* Add UI for generating invite codes

* Add tests

* Display max uses and expiration in invites table, delete invite

* Remove unused column and redundant validator

- Default follows not used, probably bad idea
- InviteCodeValidator is redundant because RegistrationsController
  checks invite code validity

* Add admin setting to disable invites

* Add admin UI for invites, configurable role for invite creation

- Admin UI that lists everyone's invites, always available
- Admin setting min_invite_role to control who can invite people
- Non-admin invite UI only visible if users are allowed to

* Do not remove invites from database, expire them instantly

* Add logging of admin actions

* Update brakeman whitelist

* Log creates, updates and destroys with history of changes

* i18n: Update Polish translation (#5782)

Signed-off-by: Marcin Mikołajczak <me@m4sk.in>

* Split admin navigation into moderation and administration

* Redesign audit log page

* 🇵🇱 (#5795)

* Add color coding to audit log

* Change dismiss->resolve, log all outcomes of report as resolve

* Update terminology (e-mail blacklist) (#5796)

* Update terminology (e-mail blacklist)

imho looks better

* Update en.yml

* Fix code style issues

* i18n-tasks normalize

* Allow staff badge to change from setting to hidden

* i18n: Update Polish translation

When a new user confirms their e-mail, bootstrap their home timeline
by automatically following a set of accounts. By default, all local
admin accounts (that are unlocked). Can be customized by new admin
setting (comma-separated usernames, local and unlocked only)

* Improve admin page

* Fix test

* Add spec

* Improve select style

* Add form for account deletion

* If avatar or header are gone from source, remove them

* Add option to have SuspendAccountService remove user record, add tests

* Exclude suspended accounts from search

* Fix #795, fix #704, fix #835 - 2FA requires confirmation to be enabled
TOTP secret is not shown again after 2FA is enabled

* Clean up