VMware: spawn refactor add VirtualMachineConfigInfo

Class to capture parameters need to build and configure
a new virtual machine instance during spawn.

partial blueprint: vmware-spawn-refactor
Change-Id: I5ed435718cd78efe01c75b9b2aac6a13da405fc2
Add API schema for v2.1/v3 user_data 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: If58e67a7fa0d256e307e565bb983c12ea131e439
Merge "Add API schema for v2.1/v3 user_data extension"
Merge "VMware: spawn refactor add VirtualMachineConfigInfo"