Implement API/driver interface for configuring vShield Edge Appliance.
Currently implemented functions:
- Deploy an Edge
- Destroy an Edge
- Configuring interfaces
- Configuring SNAT/DNAT rules
- Configuring default gateway and static routes
- Query Edge status
- Task-based asynchronous model
- Allow old routes/nat config to be skipped if new updates are coming
Implements: blueprint vcns-driver
Change-Id: I881bde907f4c90de4c919d008b76b8c2a2d0e1fd
90db4802d7