[WFLY-3045] : Expose JAXRS deployments via the management API

Displaying JAXRS resources in deployments, showing paths and  methods.
Adding mappings to the deployment infos of servlets.

Jira: https://issues.jboss.org/browse/WFLY-3045
Semantically this is not a metric, I feel ill at ease using the AbstractMetricsHandler for some runtime infos.