WildFly Readiness probe should check the suspended state of the server

A WildFly server can be suspended at multiple points during its lifecycle (when it boots, when it is gracefully shutdown).

WildFly provides readiness probes to determine when it is able to server user requests.

However, it is missing a check on its suspended state to be considered "ready".

In both the health and microprofile-smallrye-health subsystem, we should add a new readiness server probe that checks the "running-state" attribute at the root of WildFly management model. The probe should return false unless the value of the attribute is "RUNNING".

This implies that a server whose "running-state" is  one of the other "PRE_SUSPEND", "SUSPENDING", "SUSPENDED" is not ready to server user requests.