fix: compiler warnings

...ent/web/client/application/ui/AuthorizationGroupGrid.java

.../attachment/AttachmentListDeletionConfirmationDialog.java

...cation/ui/data/DataSetListDeletionConfirmationDialog.java

.../experiment/ExperimentListDeletionConfirmationDialog.java

...ient/web/client/application/ui/property/PropertyGrid.java

.../server/business/bo/samplelister/SampleListingWorker.java

...stemsx/cisd/openbis/generic/shared/util/EntityHelper.java

.../demo/client/web/client/application/DemoSampleViewer.java

.../web/client/application/dataset/GenericDataSetViewer.java

...nt/web/client/application/sample/GenericSampleViewer.java

...d/openbis/generic/server/dataaccess/db/ScriptDAOTest.java

...is/generic/server/dataaccess/db/SqlUnitMigrationTest.java

...temsx/cisd/openbis/plugin/demo/server/DemoServerTest.java

...temtest/api/v1/GeneralInformationChangingServiceTest.java