Deny ConfigDB migration when deprecated settings found

Closes #2148

See merge request pleroma/pleroma!3005

search indexing metadata should respect discoverable flag

See merge request pleroma/pleroma!2998

RichMedia: Fix log spam on failures and resetting TTL on cached errors

See merge request pleroma/pleroma!3006

# Conflicts:
#   CHANGELOG.md

Chat moderation MVP

See merge request pleroma/pleroma!2937

The factory system doesn't work too well with how the chats are
done. Instead of tempting people to use it, let's rather use the
CommonAPI system for now.

Remove unused import

See merge request pleroma/pleroma!3004

User: Remote users don't need to be confirmed or approved

Closes #2144

See merge request pleroma/pleroma!3003

ConnectionPool Worker: use monitor flush instead of checking ref

See merge request pleroma/pleroma!3002

`:flush` removes the DOWN message if one had arrived, so this check
should no longer be necessary.

Fetcher: Correctly return MRF reject reason

See merge request pleroma/pleroma!2990

Pipeline Ingestion: Video and Article

See merge request pleroma/pleroma!2908

[#2089] fix notifications

See merge request pleroma/pleroma!3000

Mastodon API: fix the public timeline returning an error when the `reply_visibility` parameter is set to `self` for an unauthenticated user

See merge request pleroma/pleroma!2999

Ensure we only apply media_nsfw simple policy on parsable objects

Closes #2133

See merge request pleroma/pleroma!2992

Remove `:managed_config` option.

Closes #2086

See merge request pleroma/pleroma!2983

In practice, it was already removed half a year ago, but the description
 and cheatsheet entries were still there.

The migration intentionally does not use ConfigDB.get_by_params, since
this will break migration code as soon as we add a new field is added
 to ConfigDB.

Closes #2086

RichMedia: fix a compilation error due to nonexistent variable

See merge request pleroma/pleroma!2996

No idea why this passed Gitlab CI

RichMedia: Do a HEAD request to check content type/length

See merge request pleroma/pleroma!2995

This shouldn't be too expensive, since the connections are pooled,
but it should save us some bandwidth since we won't fetch non-html
files and files that are too large for us to process (especially
since you can't cancel a request without closing the connection
with HTTP1).

Remove old workers in oban migrations

Closes #2139

See merge request pleroma/pleroma!2994

Translations update from Weblate

See merge request pleroma/pleroma!2991

Currently translated at 20.7% (22 of 106 strings)

Translation: Pleroma/Pleroma backend
Translate-URL: https://translate.pleroma.social/projects/pleroma/pleroma/es/