OZG-3961 refactoring; cleanup

src/main/java/de/ozgcloud/operator/Config.java

...ud/operator/keycloak/client/KeycloakClientReconciler.java

...loud/operator/keycloak/group/KeycloakGroupReconciler.java

...loud/operator/keycloak/realm/KeycloakRealmReconciler.java

...e/ozgcloud/operator/keycloak/user/KeycloakUserMapper.java

...erator/keycloak/user/KeycloakUserPreconditionService.java

...gcloud/operator/keycloak/user/KeycloakUserReconciler.java

...loud/operator/keycloak/user/UserUpdateControlBuilder.java

...gcloud/operator/keycloak/user/KeycloakUserMapperTest.java

...or/keycloak/user/KeycloakUserPreconditionServiceTest.java

...ud/operator/keycloak/user/KeycloakUserReconcilerTest.java

...perator/keycloak/user/OzgKeycloakUserSpecTestFactory.java