Increase junit coverage

.docs/api/identity-service.md

.gitlab-ci.yml

CONTRIBUTING.md

dbrepo-analyse-service/app.py

dbrepo-auth-service/dbrepo-realm.json

dbrepo-data-db/sidecar/app.py

dbrepo-data-service/metrics.md

dbrepo-data-service/pom.xml

...ice/src/main/java/at/tuwien/endpoints/AccessEndpoint.java

...e/src/main/java/at/tuwien/endpoints/DatabaseEndpoint.java

...ice/src/main/java/at/tuwien/endpoints/SubsetEndpoint.java

...vice/src/main/java/at/tuwien/endpoints/TableEndpoint.java

...rvice/src/main/java/at/tuwien/endpoints/ViewEndpoint.java

...src/main/java/at/tuwien/handlers/ApiExceptionHandler.java

...ice/rest-service/src/main/resources/application-local.yml

...a-service/rest-service/src/main/resources/application.yml

...service/src/test/java/at/tuwien/config/MariaDbConfig.java

.../test/java/at/tuwien/endpoint/AccessEndpointUnitTest.java

...est/java/at/tuwien/endpoint/DatabaseEndpointUnitTest.java

.../test/java/at/tuwien/endpoint/SubsetEndpointUnitTest.java