BIS-51 / SP-174: test cleanup

...isd/openbis/systemtest/AssignDataSetToExperimentTest.java

...sx/cisd/openbis/systemtest/AssignDataSetToSampleTest.java

...isd/openbis/systemtest/AssignExperimentToProjectTest.java

...msx/cisd/openbis/systemtest/AssignProjectToSpaceTest.java

...cisd/openbis/systemtest/AssignSampleToExperimentTest.java

...emsx/cisd/openbis/systemtest/AssignSampleToSpaceTest.java

...nbis/systemtest/RelationshipServiceAuthorizationTest.java

.../openbis/systemtest/UnassignSampleFromExperimentTest.java

.../cisd/openbis/systemtest/UnassignSampleFromSpaceTest.java

...cisd/openbis/systemtest/UpdateDataSetContainmentTest.java

...msx/cisd/openbis/systemtest/UpdateDataSetParentsTest.java

.../cisd/openbis/systemtest/UpdateSampleContainmentTest.java

...emsx/cisd/openbis/systemtest/UpdateSampleParentsTest.java

...va/ch/systemsx/cisd/openbis/systemtest/base/BaseTest.java

...ystemsx/cisd/openbis/systemtest/base/EqualityChecker.java

.../openbis/systemtest/base/ExternalDataEqualityChecker.java

.../cisd/openbis/systemtest/base/RefreshingMatcherProxy.java

...cisd/openbis/systemtest/base/StandardEqualityChecker.java

...stemsx/cisd/openbis/systemtest/base/auth/RuleBuilder.java

...emtest/base/matcher/CollectionContainsExactlyMatcher.java