Mixin removal should be prevented for a node which still has properties defined in a parent of that mixin

When a mixin is removed, there is code validation in place to ensure that if there are still public properties on that node which were brought in via the mixin, a ConstraintViolationException is thrown.

The same validation should take place not only for the properties of the mixin type itself, but for all the properties of the ancestors of that mixin as well.

Currently, if mixinA inherits from mixinB and mixinB defines a public property which is set on a node, mixinA can be removed without a problem, even though it "orphans" the property.