Add a test utility to ensure that tests use the ClientLoginModule approach for PicketBox deployments and the Elytron approach for Elytron deployments and update all affected tests

ClientLoginModule won't work when used to invoke EJBs backed by Elytron. Add a test utility to ensure that tests use the ClientLoginModule approach for PicketBox deployments and the Elytron approach for Elytron deployments when attempting to switch the user's identity. All tests that currently make use of the ClientLoginModule approach will need to be updated to make use of the new utility. This will ensure that the tests will be able to run properly with and without the Elytron profile enabled.