Add support for editing for published statuses (#16697)

* Add support for editing for published statuses

* Fix references to stripped-out code

* Various fixes and improvements

* Further fixes and improvements

* Fix updates being potentially sent to unauthorized recipients

* Various fixes and improvements

* Fix wrong words in test

* Fix notifying accounts that were tagged but were not in the audience

* Fix mistake

app/lib/activitypub/parser/custom_emoji_parser.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+class ActivityPub::Parser::CustomEmojiParser
+  include JsonLdHelper
+
+  def initialize(json)
+    @json = json
+  end
+
+  def uri
+    @json['id']
+  end
+
+  def shortcode
+    @json['name']&.delete(':')
+  end
+
+  def image_remote_url
+    @json.dig('icon', 'url')
+  end
+
+  def updated_at
+    @json['updated']&.to_datetime
+  rescue ArgumentError
+    nil
+  end
+end