Add polls (#10111)

* Add polls

Fix #1629

* Add tests

* Fixes

* Change API for creating polls

* Use name instead of content for votes

* Remove poll validation for remote polls

* Add polls to public pages

* When updating the poll, update options just in case they were changed

* Fix public pages showing both poll and other media

app/serializers/activitypub/vote_serializer.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+class ActivityPub::VoteSerializer < ActiveModel::Serializer
+  class NoteSerializer < ActiveModel::Serializer
+    attributes :id, :type, :name, :attributed_to,
+               :in_reply_to, :to
+
+    def id
+      nil
+    end
+
+    def type
+      'Note'
+    end
+
+    def name
+      object.poll.options[object.choice.to_i]
+    end
+
+    def attributed_to
+      ActivityPub::TagManager.instance.uri_for(object.account)
+    end
+
+    def to
+      ActivityPub::TagManager.instance.uri_for(object.poll.account)
+    end
+  end
+
+  attributes :id, :type, :actor, :to
+
+  has_one :object, serializer: ActivityPub::VoteSerializer::NoteSerializer
+
+  def id
+    nil
+  end
+
+  def type
+    'Create'
+  end
+
+  def actor
+    ActivityPub::TagManager.instance.uri_for(object.account)
+  end
+
+  def to
+    ActivityPub::TagManager.instance.uri_for(object.poll.account)
+  end
+end