[LMS-2048] fixed remaining tests; fixed deletion of property values in updates

...generic/server/business/bo/EntityPropertiesConverter.java

...ric/shared/managed_property/ManagedPropertyEvaluator.java

...shared/managed_property/ManagedPropertyEvaluatorTest.java

...cisd/openbis/plugin/generic/server/GenericServerTest.java

...is/systemtest/BatchMaterialRegistrationAndUpdateTest.java

...systemtest/plugin/generic/ExperimentRegistrationTest.java