SP-428, BIS-287: parent-children of samples and data sets locked. More tests.

...isd/openbis/generic/server/dataaccess/db/AbstractDAO.java

...sx/cisd/openbis/generic/server/dataaccess/db/DataDAO.java

.../cisd/openbis/generic/server/dataaccess/db/SampleDAO.java

...a/ch/systemsx/cisd/openbis/systemtest/SystemTestCase.java

...nbis/systemtest/api/v1/GeneralInformationServiceTest.java

...ystemtest/perform_entity_operations/RegistrationTest.java