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

spec/fabricators/poll_fabricator.rb

@@ -0,0 +1,8 @@
+Fabricator(:poll) do
+  account
+  status
+  expires_at  { 7.days.from_now }
+  options     %w(Foo Bar)
+  multiple    false
+  hide_totals false
+end