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

Conflicts:
- .eslintrc.yml
  Removed, as upstream removed it.
- app/controllers/admin/statuses_controller.rb
  Minor code cleanup when porting one of our features.
- app/models/account.rb
  Note length validation has changed upstream.
  We now use upstream's validation (dropped legacy glitch-soc
  account metadata stuff) but with configurable limit.
- app/services/post_status_service.rb
  Upstream has added support for scheduled toots, refactoring
  the code a bit. Adapted our changes to this refactoring.
- app/views/stream_entries/_detailed_status.html.haml
  Not a real conflict, changes too close.
- app/views/stream_entries/_simple_status.html.haml
  Not a real conflict, changes too close.

app/serializers/rest/scheduled_status_serializer.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class REST::ScheduledStatusSerializer < ActiveModel::Serializer
+  attributes :id, :scheduled_at, :params
+
+  has_many :media_attachments, serializer: REST::MediaAttachmentSerializer
+
+  def id
+    object.id.to_s
+  end
+
+  def params
+    object.params.without(:application_id)
+  end
+end