OZG-3034 Code improvements

...de/ozgcloud/alfa/resource/OzgcloudResourceController.java

...zgcloud/alfa/resource/OzgcloudResourceModelAssembler.java

...ozgcloud/alfa/resource/OzgcloudResourceRootProcessor.java

...cloud/alfa/resource/OzgcloudResourceURIResolveResult.java

.../src/test/java/de/ozgcloud/alfa/RootControllerITCase.java

...cloud/alfa/resource/OzgcloudResourceControllerITCase.java

...zgcloud/alfa/resource/OzgcloudResourceControllerTest.java

...oud/alfa/resource/OzgcloudResourceModelAssemblerTest.java

...loud/alfa/resource/OzgcloudResourceRootProcessorTest.java

...resource/OzgcloudResourceURIResolveResultTestFactory.java