Redesign admin accounts index (#9340)

* Improve overview of accounts in admin UI

- Display suspended status, role, last activity and IP prominently
- Default to showing local accounts
- Default to not showing suspended accounts

* Remove unused strings

* Fix tests

* Allow filtering accounts by IP mask

config/locales/en.yml

@@ -123,10 +123,6 @@ en:
       most_recent_ip: Most recent IP
       no_limits_imposed: No limits imposed
       not_subscribed: Not subscribed
-      order:
-        alphabetic: Alphabetic
-        most_recent: Most recent
-        title: Order
       outbox_url: Outbox URL
       perform_full_suspension: Suspend
       profile_url: Profile URL