Improve N2VC integration

This patch + https://osm.etsi.org/gerrit/#/c/5960/

 adds:
- deployment of multi-vdu vnfs
- execution of initial-config-primitives
- Handling of n2vc.login() is functional but needs optimization due to
  inner function
- Rebase

Signed-off-by: Adam Israel <adam.israel@canonical.com>
Change-Id: Ic220dca6898ffe33bf322867106562e1340d6571