Add appeals (#17364)

* Add appeals

* Add ability to reject appeals and ability to browse pending appeals in admin UI

* Add strikes to account page in settings

* Various fixes and improvements

- Add separate notification setting for appeals, separate from reports
- Fix style of links in report/strike header
- Change approving an appeal to not restore statuses (due to federation complexities)
- Change style of successfully appealed strikes on account settings page
- Change account settings page to only show unappealed or recently appealed strikes

* Change appealed_at to overruled_at

* Fix missing method error

app/views/admin/report_notes/_report_note.html.haml

@@ -3,7 +3,7 @@
 
   .report-notes__item__header
     %span.username
-      = link_to display_name(report_note.account), admin_account_path(report_note.account_id)
+      = link_to report_note.account.username, admin_account_path(report_note.account_id)
     %time{ datetime: report_note.created_at.iso8601, title: l(report_note.created_at) }
       - if report_note.created_at.today?
         = t('admin.report_notes.today_at', time: l(report_note.created_at, format: :time))