[feature/avatars] Reduce module auth of ucp avatar settings

Previously the avatar types that need to be enabled were hardcoded into
the module auth. This is no longer needed in the new avatar system.

PHPBB3-10018
[feature/avatars] Add migrations data file for avatars

The module_auth of the ucp avatar settings are used for checking if the
migration has already been installed.

PHPBB3-10018