[ticket/12419] Improve font size in notifications drop-down

PHPBB3-12419
[ticket/12419] Also shrink the size of "See All" in footer a little bit

PHPBB3-12419
Merge remote-tracking branch 'VSEphpbb/ticket/12419' into develop-ascraeus

* VSEphpbb/ticket/12419:
  [ticket/12419] Also shrink the size of "See All" in footer a little bit
  [ticket/12419] Improve font size in notifications drop-down