Rename get_pending_acl_package and make it more flexible

Adjust unit-tests
Rename the get_pending_acl_user_package to get_acl_user_package

Adjust the API method to the backend one which is now more flexible

Adjust unit-tests accordingly
Fix redirection and the use of the new API

Update should always work, not only for pending ACLs since it's used to.. update
Layout change when updating the ACLs of a package