OZG-2653 Readme um properties erweitert. Fehler in findByEMail gefixed

README.md

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

src/main/resources/application-dev.yaml

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

...va/de/itvsh/kop/user/keycloak/KeycloakApiServiceTest.java

src/test/java/de/itvsh/kop/user/sync/SyncServiceTest.java