[ticket/12664] Refactor develop/migration_tips.php into a console command.

PHPBB3-12664
Merge pull request #2569 from bantu/ticket/12664

[ticket/12664] Refactor develop/migration_tips.php into a console command.

* bantu/ticket/12664:
  [ticket/12664] Refactor develop/migration_tips.php into a console command.
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12664] Refactor develop/migration_tips.php into a console command.