``exclude-protected`` using the class name and attribute name (astroid's ``qname``) instead of only the attribute name

[Pierre-Sassoulas]

Current problem

Right now only the name is taken into account. For example if we want to make os._exit permissible we'd make all x._exit permissible.

Desired solution

We use the qname instead so we can allow one off class/attr combination.

Additional context

See #6473