OZG-2220 refactoring after code review, move method

...erver/src/main/java/de/itvsh/kop/user/UserRepository.java

...r-server/src/main/java/de/itvsh/kop/user/UserService.java

...organisationseinheit/OrganisationsEinheitGrpcService.java

.../organisationseinheit/OrganisationsEinheitRepository.java

...ser/organisationseinheit/OrganisationsEinheitService.java

...src/test/java/de/itvsh/kop/user/UserRepositoryITCase.java

...r/src/test/java/de/itvsh/kop/user/UserRepositoryTest.java

...rver/src/test/java/de/itvsh/kop/user/UserServiceTest.java

...isationseinheit/OrganisationsEinheitRepositoryITCase.java

...anisationseinheit/OrganisationsEinheitRepositoryTest.java

...organisationseinheit/OrganisationsEinheitServiceTest.java

...nisationseinheit/OrganisationseinheitGrpcServiceTest.java