[ticket/11443] Add _test suffix to migration test filenames

PHPBB3-11443
[ticket/11443] Fix Migrator Modules Tool by creating a phpbb_log object

PHPBB3-11443
Merge remote-tracking branch 'nickvergessen/ticket/11443' into develop

* nickvergessen/ticket/11443:
  [ticket/11443] Fix Migrator Modules Tool by creating a phpbb_log object
  [ticket/11443] Add _test suffix to migration test filenames