Entity-Annotation should reference owning Aggregate

[StephanPirnbaum]

The interface org.jmolecules.ddd.types.Entity has generics to specify the aggregate root the entity belongs to. However, for the annotation, this is currently not the case. To have this consistent I propose to add an optional parameter to the @Entity annotation to specify the aggregate root. This would allow tools such as ArchUnit or jQAssistant to validate access to entities.

Opinions?