Follow-up to #8142

* Add separate setting for sidebar text (site_short_description)

* Fix tests

Upstream's implementation has been merged a while ago and is the preferred
way to set fields, as it is the only one compatible with upstream and is
more user-friendly.

This commit deletes the legacy glitch-soc FrontMatter functionality in order
to clean up the code and make it easier to maintain.

* Add federation relay support

* Add admin UI for managing relays

* Include actor on relay-related activities

* Fix i18n

* Add option to not consider word boundaries when filtering phrases

* Add a few tests for keyword/phrase filtering

* 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

* Add more granular OAuth scopes

* Add human-readable descriptions of the new scopes

* Ensure new scopes look good on the app UI

* Add tests

* Group scopes in screen and color-code dangerous ones

* Fix wrong extra scope

* 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

* Add keyword filtering

    GET|POST       /api/v1/filters
    GET|PUT|DELETE /api/v1/filters/:id

- Irreversible filters can drop toots from home or notifications
- Other filters can hide toots through the client app
- Filters use a phrase valid in particular contexts, expiration

* Make sure expired filters don't get applied client-side

* Add missing API methods

* Remove "regex filter" from column settings

* Add tests

* Add test for FeedManager

* Add CustomFilter test

* Add UI for managing filters

* Add streaming API event to allow syncing filters

* Fix tests

* Allow selecting default posting language instead of auto-detect

* Enable default language setting in credentials API

* Fix form saving

* Switch filtered_languages to chosen_languages

* Adjust interface

* Remove unused translations

* Add autofollow option to invites

* Trigger CodeClimate rebuild

This is a bit hackish. The best way would simply to somehow
use Mastodon's ApplicationController with `use_pack 'error'` from
the Rake task, but I'm not sure how to do that.

* Add preference to hide following/followers lists

- Public pages
- ActivityPub collections (does not return pages but does give total)
- REST API (unless it's your own) (does not federate)

Fix #6901

* Add preference

* Add delegation

* Fix issue

* Fix issue

* Distinguish boosts from original statuses in the admin panel (fixes #7449)

* Show the “show more” button in admin view to make CWs clearer (fixes #7451)

* Make content warnings swag

* Store actor type in database

* Add bot nameplate to web UI, add setting to preferences, API, AP
Fix #7365

* Fix code style issues

Follow-up to #6124

* Add confirmations_controller#resend

* Add tests for confirmations_controller#resend

* Add translations

* Improve design of account statuses admin UI (consistent with reports)

* Make account moderation notes look consistent with report notes

* i18n-tasks remove-unused

* Fix code style issues

* Fix tests

Fix #7335

Fix #6994

25ms -> 0.5ms

* 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)

glitch-soc-style still in backup, both sharing the same SCSS style

* 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