NFD

In IntegrationTests, eliminate the separate nfdc create step.

Background:
Initially, nfdc register, nfdc unregister, nfdc add-nexthop, nfdc remove-nexthop, nfdc destroy commands do not accept FaceUri, so that scenarios must invoke nfdc create, parse its output to get FaceId, and pass the FaceId to those commands.
Now those commands can accept FaceUri directly and therefore do not need a separate nfdc create step.