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/ko.yml

@@ -123,10 +123,6 @@ ko:
       most_recent_ip: 최근 IP
       no_limits_imposed: 제한 없음
       not_subscribed: 구독하지 않음
-      order:
-        alphabetic: 알파벳 순
-        most_recent: 최근 순
-        title: 순서
       outbox_url: 발신함 URL
       perform_full_suspension: 정지시키기
       profile_url: 프로필 URL