Add support for private pinned posts (#16954)

* Add support for private pinned toots

* Allow local user to pin private toots

* Change wording to avoid "direct message"

app/lib/activitypub/activity/add.rb

@@ -4,8 +4,7 @@ class ActivityPub::Activity::Add < ActivityPub::Activity
   def perform
     return unless @json['target'].present? && value_or_id(@json['target']) == @account.featured_collection_url
 
-    status   = status_from_uri(object_uri)
-    status ||= fetch_remote_original_status
+    status = status_from_object
 
     return unless !status.nil? && status.account_id == @account.id && !@account.pinned?(status)