WFLY-963: adds support for jndi modifications by modules/extensions, at ...

...the writable service based naming store. The only change in the API is that now the owner may in alternative be a service target. In such case new binder services are installed in the provided service target, which was the old behaviour, which works fine for modules/extensions. 

The PR also improves the management of references/owners of binder services, and fixes the naming store logic for rebind and unbind operations. A new integration test is also provided to ensure that shared bindings are handled correctly.