Add rights and copyrights to resource

[dennis-ruhe-npo]

Adds ec:hasRights and ec:hasCopyright to ec:Resource

We require ec:hasCopyright on our ec:Picture subjects. Adding them on ec:Resource seemed appropriate.

[JuergenGrupp]

Hi @dennis-ruhe-npo , thank you for your merge request. The Editorial Committee has discussed the issue and proposes a slightly different solution to your problem:

The class Picture will become a subclass of MediaResource. This allows Picture to link via instantiates to an EditorialObject and to Rights and Copyrights from there.

This retains to the principle that Rights are associated to EditorialObjects, no matter what physical representation as Resource it has.

The changes will be applied once the current restructuring of language packs is completed.
See #510

[aro-max]

Thank you @dennis-ruhe-npo

At the moment, ec:hasRights and ec:hasCopyright belong on the Asset side of the model and are therefore inherited to ec:EditorialObject. For that reason, we do not think we should solve this by adding rights directly to ec:Resource, since that would broaden the rights model for the whole Resource hierarchy.

The real modeling question seems to be how ec:Picture should be positioned so that both its editorial/content aspect and its physical/resource aspect can be represented consistently.

Several alternatives were discussed, including a more specific modeling of Picture and a possible additional class to separate the editorial/content perspective from the physical/resource perspective. My understanding is that this structural direction should be addressed first, as discussed in #510, rather than merging the current PR as it stands.

Thank you again for the contribution and for documenting the use case.