[ticket/12890] Search by custom profile fields for members

Still a work in progress, requires work for field-specific scenarios such as the date field and requires work on finishing the templates for memberlist

[PHPBB3-12890](https://tracker.phpbb.com/browse/PHPBB3-12890)


Sorry for the late response but [they have](https://github.com/Dragooon/phpbb/blob/ticket/12890/phpBB/phpbb/profilefields/type/type_bool.php)?