ISPN-4478 ServerFailureRetrySingleOwnerTest should remove listener

* Before, the error inducing listener was not being removed, and that
was not appearing as a result that each test was creating a new bunch
of cache managers. Now, clean up is done after the test class has
finished and the listeners are correctly removed.
ISPN-4499 Prevent shadowing user-defined jgroups configuration file
ISPN-4195 Clarify how L1 lifespan controls enabling/disabling it
ISPN-4541 release.py script fails due to as-modules split
ISPN-3950 Move KeyValueFilterFactory and ConverterFactory to core

* Moved to core/ to make it easier for users to implement factory
instances and avoid leaking server/hotrod components.
ISPN-3950 WIP...