Create DNS comparison command for privileged users.
Create DNS comparison command for privileged users.

Back when we had a discrepancy in DNS results, we were afraid SmokeDetector might be a part of it.  Which is what let ArtOfCode to create the `dig` command, so we could look at DNS results returned by SmokeDetector.

With the recent changes done to SmokeDetector with #6541, we now have the capacity to customize SmokeDetector's DNS settings and configurations.  Which means that having a customizable DNS means we need a mechanism to compare DNS output from SmokeDetector's DNS settings and a reliable DNS server.  In this case, I chose Google DNS as a comparative server for our use to compare against whatever DNS setup is done on SmokeDetector instances, whether system configured DNS or customized DNS with individual SD instances.

Charcoal-SE/SmokeDetector,Charcoal-SE/SmokeDetector