o-a-ctl-region: minor improvements

1. Use the list of commands instead of a regex
2. Validate parameters before loading the broker
o-a-ctl-district: minor improvements

1. Use the list of commands instead of a duplicating regex
2. Validate parameters before loading the broker
(and don't require loading broker just to show usage)
Merge pull request #4872 from sosiouxme/ctl-region

Merged by openshift-bot