When a wildcard namespace is used for `nomad job` commands that support prefix
matching, avoid asking the user for input if a prefix is an unambiguous exact
match so that the behavior is similar to the commands using a specific or
unset namespace.
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 PR moves creating the API client into the returned predict
function. The creation of the client causes a lookup of all the system
certificates and doing that for each command on mac was extremely slow.
Tim Gross