Make testing for moderator state centralized in User class

web/components/chat/chat.js

@@ -140,15 +140,3 @@ export function emojify(HTML, emojiList) {
   }
   return HTML;
 }
-
-// MODERATOR UTILS
-export function checkIsModerator(message) {
-  const { user } = message;
-  const { scopes } = user;
-
-  if (!scopes || scopes.length === 0) {
-    return false;
-  }
-
-  return scopes.includes('MODERATOR');
-}