Enforce scope check always when rule has scope_types set

Previously it was checked only for registered rules but not for
rules which are subclasses of the BaseCheck class.
Now it's checked for all rules which have scope_types set.

It's required for e.g. Neutron as it is creating Check objects based
on the defined policy rules to e.g. include in the check attributes
like network's provider parameters, etc.

Depends-On: https://review.opendev.org/c/openstack/neutron/+/815838
Depends-On: https://review.opendev.org/c/openstack/neutron/+/818725

Closes-Bug: #1923503
Change-Id: I55258c1f999c84220518d1fbbf5e1e514361cebe