Get rid of temporary ModelUtils and FailedOperationTransformationConfig in EJB 3 transformer tests

WFCORE-1892 introduces new stricter checking which needs some improvements in the EJB3 transformer tests. More functionality has been added to the test framework to make this possible, as an interim solution EJB3 contains a copy of the classes mentioned in this issue, in order to get the tests to pass with the improvements in the EJB3 tests.