Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `app/lib/formatter.rb`:
  Upstream completely refactored the formatting code and removed that file,
  while glitch-soc had code for Markdown and HTML toots.
  Took upstream code, glitch-soc changes will be re-implemented on top of the
  refactored classes in a later commit.
- `app/models/status.rb`:
  Upstream refactored status edit handling and moved code to
  `app/models/concerns/status_snapshot_concern.rb`.
  Applied glitch-soc's changes to that file.
- `app/serializers/activitypub/note_serializer.rb`:
  Not really a conflict, just a line added too close to one modified by
  glitch-soc.
  Applied upstream changes while keeping the glitch-soc-modified one.
- `app/services/update_status_service.rb`:
  Not really a conflict, upstream modified a line adjacent to one added by
  glitch-soc.
  Applied upstream changes while keeping the glitch-soc line.
- `app/views/statuses/_simple_status.html.haml`:
  Upstream refactored formatting, glitch-soc changed the markup slightly.
  Applied upstream changes.
- `spec/lib/formatter_spec.rb`:
  Upstream completely refactored the formatting code and removed that file,
  while glitch-soc had code for Markdown and HTML toots.
  Took upstream code, glitch-soc changes will be re-implemented on top of the
  refactored classes in a later commit.

app/serializers/activitypub/note_serializer.rb

@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class ActivityPub::NoteSerializer < ActivityPub::Serializer
+  include FormattingHelper
+
   context_extensions :atom_uri, :conversation, :sensitive, :voters_count, :direct_message
 
   attributes :id, :type, :summary,
@@ -50,11 +52,11 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
   end
 
   def content
-    Formatter.instance.format(object)
+    status_content_format(object)
   end
 
   def content_map
-    { object.language => Formatter.instance.format(object) }
+    { object.language => content }
   end
 
   def replies