Regional Edge Orchestrator support

Purpose:

Thin edges can be headless. A regional controller, in this case, can be edge controller for many edge sites.  ONAP communicates with a regional controller for a set of edges. 

At this time, each site is registered with ONAP.  Each edge has its own control and same is reflected in ONAP.

With one regional controller supporting multiple edge locations, ONAP should ensure that it can talk to regional controller on behalf of edges.

Based on ESR and A&AI capabilities we see in R2,  we believe that regional controllers can be supported, but we need to verify.

As part of this effort, intention is create edge orchestrator using K8S and verify that multiple headless edges can be used to deploy VNFs using central K8S orchestrator.