NSO verify did not handle leaf-list value verification in 4.5 and
later due to changes made for configuration writing made.
map prefix for identityref types in verification.
* update version parsing and move requirements to nso_* modules
prepare for introduction of nso_show module that has other version
requirements than the existing nso_* modules.
* Add nso_show module for retreiving config from Cisco NSO
New module that supports getting configuration and operational data
from Cisco NSO.