Add ability to view previous edits of a status in admin UI (#19462)

* Add ability to view previous edits of a status in admin UI

* Change moderator access to posts to be controlled by a separate policy

app/models/status_edit.rb

@@ -30,7 +30,7 @@ class StatusEdit < ApplicationRecord
              :preview_remote_url, :text_url, :meta, :blurhash,
              :not_processed?, :needs_redownload?, :local?,
              :file, :thumbnail, :thumbnail_remote_url,
-             :shortcode, to: :media_attachment
+             :shortcode, :video?, :audio?, to: :media_attachment
   end
 
   rate_limit by: :account, family: :statuses
@@ -40,7 +40,8 @@ class StatusEdit < ApplicationRecord
 
   default_scope { order(id: :asc) }
 
-  delegate :local?, to: :status
+  delegate :local?, :application, :edited?, :edited_at,
+           :discarded?, :visibility, to: :status
 
   def emojis
     return @emojis if defined?(@emojis)
@@ -59,4 +60,12 @@ class StatusEdit < ApplicationRecord
       end
     end
   end
+
+  def proper
+    self
+  end
+
+  def reblog?
+    false
+  end
 end