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/views/statuses/_poll.html.haml

@@ -1,15 +1,19 @@
 - show_results = (user_signed_in? && poll.voted?(current_account)) || poll.expired?
+- own_votes = user_signed_in? ? poll.own_votes(current_account) : []
 
 .poll
   %ul
-    - poll.loaded_options.each do |option|
+    - poll.loaded_options.each_with_index do |option, index|
       %li
         - if show_results
           - percent = poll.votes_count > 0 ? 100 * option.votes_count / poll.votes_count : 0
           %span.poll__chart{ style: "width: #{percent}%" }
 
           %label.poll__text><
-            %span.poll__number= percent.round
+            %span.poll__number><
+              - if own_votes.include?(index)
+                %i.poll__vote__mark.fa.fa-check
+              = percent.round
             = Formatter.instance.format_poll_option(status, option, autoplay: autoplay)
         - else
           %label.poll__text><