SCE — Annotation class provides no value and conflicts with downstream languages

The Annotation class, an abstract class, is no longer necessary since Documentation and Category are no longer subclassing it. With only Attachment subclassing Annotation, it provides no value. It also adds additional structural overhead that is not needed. Further, using the name "Annotation" conflicts with downstream language PPMN that want to use it for an unrelated language element.

Remove Annotation

Remove Annotation Class from Metamodel and Schema