[ticket/12796] Add view own profile to UCP (and vice versa)

PHPBB3-12796
[ticket/12796] Use &amp; in path

PHPBB3-12796
[ticket/12796] Use dedicated lang vars

PHPBB3-12796
Merge remote-tracking branch 'PayBas/ticket/12796' into develop-ascraeus

* PayBas/ticket/12796:
  [ticket/12796] Use dedicated lang vars
  [ticket/12796] Use &amp; in path
  [ticket/12796] Add view own profile to UCP (and vice versa)