Enable tests requiring atp/wsgen on client side

The testsuite has excluded tests because of the missing wrapper generator. Once this is available, we can deploy the same testsuite jars on Native and Metro, without requiring users to run an external tool when developing endpoints with bottom-up (java first) strategy.
However Metro still need to generate wrapper beans on client side to invoke the service. In a real world scenario, where client and server do not share classes, users would run wsimport and obtain the required classes from the service contract. Thus no wrapper generation required on client side.
We should anyway be able to run our full testsuite with Metro stack, so we need to somehow enhance our test framework to automatically call wsgen when requiring a give artifact to be deployed before running some tests. This would provide the missing piece on client side for running those tests.