Support more variations of ActivityPub keyId in signature (#4630)

- Tries to avoid performing HTTP request if the keyId is an actor URI
- Likewise if the URI is a fragment URI on top of actor URI
- Resolves public key, returns owner if the owner links back to the key

app/lib/activitypub/activity.rb

@@ -58,7 +58,7 @@ class ActivityPub::Activity
   end
 
   def object_uri
-    @object_uri ||= @object.is_a?(String) ? @object : @object['id']
+    @object_uri ||= value_or_id(@object)
   end
 
   def redis

app/lib/activitypub/activity/accept.rb

@@ -20,6 +20,6 @@ class ActivityPub::Activity::Accept < ActivityPub::Activity
   end
 
   def target_uri
-    @target_uri ||= @object['actor']
+    @target_uri ||= value_or_id(@object['actor'])
   end
 end

app/lib/activitypub/activity/reject.rb

@@ -20,6 +20,6 @@ class ActivityPub::Activity::Reject < ActivityPub::Activity
   end
 
   def target_uri
-    @target_uri ||= @object['actor']
+    @target_uri ||= value_or_id(@object['actor'])
   end
 end

app/lib/activitypub/activity/undo.rb

@@ -64,6 +64,6 @@ class ActivityPub::Activity::Undo < ActivityPub::Activity
   end
 
   def target_uri
-    @target_uri ||= @object['object'].is_a?(String) ? @object['object'] : @object['object']['id']
+    @target_uri ||= value_or_id(@object['object'])
   end
 end

app/lib/activitypub/tag_manager.rb

@@ -93,7 +93,7 @@ class ActivityPub::TagManager
     elsif ::TagManager.instance.local_id?(uri)
       klass.find_by(id: ::TagManager.instance.unique_tag_to_local_id(uri, klass.to_s))
     else
-      klass.find_by(uri: uri)
+      klass.find_by(uri: uri.split('#').first)
     end
   end
 end