Remove the all_attributes Function

[InsertCreativityHere]

This function was added solely to support our old semantics of cs::namespace
(where it could be applied to multiple nested modules and we'd check the attributes on all of them).
So now that these semantics have been reworked into something more reasonable this function should be deleted.

However, this function started getting used as a hacky replacement for the include_parents flag which was removed in #574.
We should find some other way of checking parent attributes that doesn't involve all_attributes so it can be properly deleted.