Improve admin UI for accounts (#7360)

* Improve design of account statuses admin UI (consistent with reports)

* Make account moderation notes look consistent with report notes

* i18n-tasks remove-unused

* Fix code style issues

* Fix tests

app/javascript/styles/mastodon/admin.scss

@@ -336,7 +336,8 @@
   }
 }
 
-.simple_form.new_report_note {
+.simple_form.new_report_note,
+.simple_form.new_account_moderation_note {
   max-width: 100%;
 }