[ticket/12685] New CLI container for load extensions

https://tracker.phpbb.com/browse/PHPBB3-12685

PHPBB3-12685
the other branch was only for me, to have a look (because I miss understood something^^)
So, in this branch, make this changes https://github.com/phpbb/phpbb/pull/2576#discussion_r14924332 but use getParameterOption() instead of getOption() and it should be good.

Sorry for the confusion.