Extract component to show moderation actions

Note that in proposal notifications we're writing the call to
render the component in the same line as the <div class="reply">
definition in order to be able to use the `:empty` selector when the
component renders nothing. No browser matches whitespace with the
`:empty` selector, so we can't add newline characters inside the tag. A
more elegant solution would be extracting the proposal notification
actions to a component and only rendering it if the moderation actions
component is rendered.

app/models/comment.rb

@@ -83,6 +83,10 @@ class Comment < ApplicationRecord
     self.user = author
   end
 
+  def human_name
+    body.truncate(32)
+  end
+
   def total_votes
     cached_votes_total
   end