[Azure CNS] Register azure-cns as windows service

Azure Batch team uses Azure-CNS for ADF works. We run azure-cns.exe (only windows) as standalone executable at individual VM.

However, we need register azure-cns.exe as windows service so it will restart when it crashes or start automatically when VM reboot.

We would like the feature for azure-cns to add a new flag which can register itself as windows service.