added tenantId/projectId to volume and snapshot

added tenant id to  volume and project id to snapshot
> nope the field name is "metadata"...

@nacx Just to clarify my understanding: is it better to have `@Named` on attributes where the name is the same as the annotation, or is that unnecessary? I recall some discussion about this making a difference in terms or forcing the code to do reflection, or something like that...but would rather ask to clarify ;-)