The only user of monitor(evalID, true) was command/eval_status, and
eval_status had a duplicate of the prefix-handling code inside it, so in
all cases the complete evalID was being passed to monitor.
Given that, we can remove the prefix code from command/monitor, and
remove the boolean arg.
This adds a `nomad alloc stop` command that can be used to stop and
force migrate an allocation to a different node.
This is built on top of the AllocUpdateDesiredTransitionRequest and
explicitly limits the scope of access to that transition to expose it
under the alloc-lifecycle ACL.
The API returns the follow up eval that can be used as part of
monitoring in the CLI or parsed and used in an external tool.