Show user what options they have voted (#11195)

* Add own_votes field to poll results in REST API

Fixes #10679

* Display user votes in WebUI

* Update styling

* Add vote checkmark to public pages

app/serializers/rest/poll_serializer.rb

@@ -8,6 +8,7 @@ class REST::PollSerializer < ActiveModel::Serializer
   has_many :emojis, serializer: REST::CustomEmojiSerializer
 
   attribute :voted, if: :current_user?
+  attribute :own_votes, if: :current_user?
 
   def id
     object.id.to_s
@@ -21,6 +22,10 @@ class REST::PollSerializer < ActiveModel::Serializer
     object.voted?(current_user.account)
   end
 
+  def own_votes
+    object.own_votes(current_user.account)
+  end
+
   def current_user?
     !current_user.nil?
   end