Add support for custom emojis in poll options (#10322)

* Backend changes for custom emoji support in poll options

* Serialize poll emojis in REST API

* Render custom emojis in poll options

* Render custom emoji in poll options on public pages

app/models/poll.rb

@@ -60,6 +60,10 @@ class Poll < ApplicationRecord
     !local?
   end
 
+  def emojis
+    @emojis ||= CustomEmoji.from_text(options.join(' '), account.domain)
+  end
+
   class Option < ActiveModelSerializers::Model
     attributes :id, :title, :votes_count, :poll