Commands for managing static IP addresses

Added commands:
azure vm static-ip show <vm-name>
azure vm static-ip set <vm-name> <ip-address>
azure vm static-ip remove <vm-name>
azure network vnet static-ip check <vnet> <ip-address>

Added --static-ip option to:
azure vm create
azure vm docker create

@babumuralidharan it seems that all bugs on this feature have been addressed.
@avranju , please review. This PR is assuming we want to merge into MSOT/dev and not send directly upstream.
Agree. I wasn't sure about that either but seems like a good thing to do. And yes, the utility routine falls back to simply returning the string that's passed in if it can't find the localized equivalent.