Add unit tests

...ain/java/eu/europa/ec/edelivery/smp/data/dao/UserDao.java

...ec/edelivery/smp/data/model/DBDomainDeleteValidation.java

...opa/ec/edelivery/smp/services/ServiceMetadataService.java

.../ec/edelivery/smp/config/SmlIntegrationConfiguration.java

...pa/ec/edelivery/smp/data/dao/AbstractResourceDaoTest.java

...pa/ec/edelivery/smp/data/dao/AlertDaoIntegrationTest.java

...uropa/ec/edelivery/smp/data/dao/AuditIntegrationTest.java

...java/eu/europa/ec/edelivery/smp/data/dao/BaseDaoTest.java

...ry/smp/data/dao/ResourceDaoMembershipIntegrationTest.java

...smp/data/dao/ServiceGroupDaoOwnershipIntegrationTest.java

...opa/ec/edelivery/smp/data/dao/UserDaoIntegrationTest.java

...delivery/smp/services/AbstractServiceIntegrationTest.java

...entFactoryAuthenticationByClientCertFromKeystoreTest.java

...u/europa/ec/edelivery/smp/sml/SmlConnectorDomainTest.java

...java/eu/europa/ec/edelivery/smp/testutil/TestDBUtils.java

...est/resources/keystores/smp-keystore_multiple_domains.jks