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/javascript/styles/mastodon/components.scss

@@ -105,6 +105,10 @@
       border-color: lighten($ui-primary-color, 4%);
       color: lighten($darker-text-color, 4%);
     }
+
+    &:disabled {
+      opacity: 0.5;
+    }
   }
 
   &.button--block {