Add API schema for v2.1 access_ips extension

By defining the API schema, it is possible to separate the validation
code from the API method. The API method can be more simple.
In addition, a response of API validation error can be consistent for
the whole Nova API.

Partially implements blueprint v3-api-schema

Change-Id: I495e7538e5d8d67f19792dfa0427ab7a1b0068cf
VMware: Remove VMwareVCVMOps

This support is no longer needed as we only support the VC driver
since commit 1deb31f85a8f5d1e261b2cf1eddc537a5da7f60b.

The patch makes use of VMwareVMOps. All of the specific VC methods
are moved into this class.

partial blueprint vmware-spawn-refactor

Change-Id: Ieb2198a956853c75855e3b4441cc3a893b2e6079
Merge "VMware: Remove VMwareVCVMOps"
Merge "Add API schema for v2.1 access_ips extension"