[ticket/12380] Sort Remember Me keys by last login time in UCP

PHPBB3-12380
[ticket/12380] Explicity state the order of sorting for login keys

PHPBB3-12380
Merge remote-tracking branch 'vsephpbb/ticket/12380' into develop-ascraeus

* vsephpbb/ticket/12380:
  [ticket/12380] Explicity state the order of sorting for login keys
  [ticket/12380] Sort Remember Me keys by last login time in UCP