Ability to read the underlying JNDI datasource name

Some jBPM modules (currently the jBPM console only), might need to know what is the JNDI name of the underlying datasource used by the jBPM's persistence layer.

The jBPM console, in particular, needs this in order to configure the datasets that feed the different jBPM consoles as well as the process and tasks dashboards.

Basically, the feature requested here is to provide a helper class that exposes the JPA's datasource settings to other platform modules.