[WFCORE-353] : CLI command for executing the deployment scanner.

Adding a new operation that will run a single scan.

Jira: https://issues.jboss.org/browse/WFCORE-353
Won't this deadlock? 

Ah, it doesn't deadlock because you passed 'false' to getServiceRegistry(). So the op executing this call doesn't hold the exclusive lock, allowing the ModelControllerClient held by the scanner to execute another op and get the lock.

But if this were called inside a composite op and some other step acquired the lock, this would deadlock.

I fear this is harder than we thought, and something like what is done at boot will need to be done, to get the scanner to prepare a set of ops and then they get executed in the context of this op. But that's hard too, as this step happens in Stage.RUNTIME, while the scanner ops need to be in MODEL.