Support for NVP advanced FwaaS service

Support for NVP advanced FwaaS service

The patch adds advanced FWaaS service support for NVP with
VCNS:
        * NVP FWaaS is an advanced Service of NVP depending on NVP
          advanced service router
            - Once an advanced router id created, one corresponding
              vshield edge will be deployed, and then we can configure
              FW service on the vshield edge
        * NVP FWaaS service plugin still uses FWaaS DB service logic,
          while finally calling vShield Edge to support FWaaS service
            - When firewall object is created, we will attach the
              object to the advanced router with routedserviceinsertion_db
              service
        * on driver part, the driver will first convert the object
          to VSM known object input, and then send a synchronous JSON
          calling to VSM, and receive the result

Implements: blueprint nvp-fwaas-plugin
Change-Id: Id43af8821f5c553356e3cc870993eef99ef7def3