OZG-7350 implement GrpcCreateCollaborationRequestData with Fachstelle

...g-manager-interface/src/main/protobuf/vorgang.model.proto

.../ozgcloud/vorgang/collaboration/CollaborationService.java

...gang/collaboration/CreateCollaborationVorgangRequest.java

...ollaboration/CreateCollaborationVorgangRequestMapper.java

...in/java/de/ozgcloud/vorgang/collaboration/Fachstelle.java

...a/de/ozgcloud/vorgang/collaboration/FachstelleMapper.java

...cloud/vorgang/collaboration/CollaborationServiceTest.java

...boration/CreateCollaborationVorgangRequestMapperTest.java

...oration/CreateCollaborationVorgangRequestTestFactory.java

.../ozgcloud/vorgang/collaboration/FachstelleMapperTest.java

...ozgcloud/vorgang/collaboration/FachstelleTestFactory.java

...ration/GrpcCreateCollaborationRequestDataTestFactory.java

...loud/vorgang/collaboration/GrpcFachstelleTestFactory.java