Fixes a lot of warnings like the following while running the testsuite:

  warning: passing a {module, function, args} tuple to Plug.Parsers.MULTIPART is deprecated. Please see Plug.Parsers.MULTIPART module docs for better approaches to configuration

This might mean no more dynamic configuration but there seems to be the same limitation two lines underneath anyway.

Add missing deprecation warning left out of !2842

See merge request pleroma/pleroma!3444

Erlang 24 compatibility

Closes #2647

See merge request pleroma/pleroma!3405

This brings them more in line with Mastodon.
- Deduplicates display name from the title and content
- Removes arbitrary limits on the size of the embedded image
- Removes angled double quotes from embed descriptions. These would normally just indicate that the content is a quote, but that is already implied by the content being in an embed.

Since mime 1.6.0:

  warning: MIME.valid?/1 is deprecated. Use MIME.extensions(type) != [] instead

As for the bitstring(type) part it's because MIME.extensions only expects a string.
https://github.com/elixir-plug/mime/issues/43

Rename the non-federating Chat feature to Shout

See merge request pleroma/pleroma!2842

Skip CI/CD automatically under certain conditions

See merge request pleroma/pleroma!3439

Update docs/description for allow_relay

See merge request pleroma/pleroma!3438

Recompilation speedup: Avoid `use Phoenix.Swoosh` to prevent recompiling the Endpoint

See merge request pleroma/pleroma!3436

Speeds up recompilation by fixing cycles in UserEmail

Recompilation speedup: Remove deps from Streaming/Persisting behaviors

See merge request pleroma/pleroma!3434

Recompilation speedup: Remove deps from Uploader behaviour

See merge request pleroma/pleroma!3435

There is no sane / high level workaround for merging users who join shout:public and chat:public.

Speeds up recompilation by limiting compile-time deps

Speeds up recompilation by limiting compile-time deps

Legacy PleromaFE uses this to identify if ShoutBox is available.

Recompilation speedup: move as_local_public/0 into ActivityPub.Utils

See merge request pleroma/pleroma!3431

Recompilation speedup: make Router a runtime dep of FrontendStatic

See merge request pleroma/pleroma!3429

Deprecate Pleroma.Web.base_url/0

See merge request pleroma/pleroma!3432