Add animate custom emoji param to embed pages (#8507)

* Add animate custom emoji param to embed pages

* Rename param, use it for avatars and gifs

* Fix issues pointed by codeclimate and breaking test

* Ignore brakeman warning

spec/views/stream_entries/show.html.haml_spec.rb

@@ -12,6 +12,7 @@ describe 'stream_entries/show.html.haml', without_verify_partial_doubles: true d
     allow(view).to receive(:full_asset_url).and_return('//asset.host/image.svg')
     allow(view).to receive(:local_time)
     allow(view).to receive(:local_time_ago)
+    allow(view).to receive(:current_account).and_return(nil)
     assign(:instance_presenter, InstancePresenter.new)
   end