Fix potentially extreme bugs caused by unconditional use of hook_civicrm_aclGroup

Despite its name, hook_civicrm_aclGroup is not only for groups, but is used to apply acl filters via hook to various tables including custom field groups and profile fields. Unconditionally running this hook without taking that into account is likely to cause havoc and mayhem throughout the system as various entities will inexplicably go missing for certain users.