Adds tests for Hyper-V VM Utils

Adds unit tests for Hyper-V VMUtils and VMUtilsV2 classes.

Co-Authored-By: Bogdan Teleaga <bteleaga@cloudbasesolutions.com>

Partial-Bug: #1220256

Change-Id: I87a13697b0a83dc8905573081f735b542bc9bf17
nova-network: treat instance like object in allocate_for_instance

The allocate_for_instance method gets an instance object from the
compute manager so treat it like an object by using dot notation.

This change updates the docstrings for the base API and nova-network API
methods and updates the nova-network API unit tests to use instance
objects when testing allocate_for_instance.

Part of blueprint compute-manager-objects-juno

Change-Id: Ia6d1d8dd46820d48cd9a3f3d4e98fb48e85d1188
neutronv2: treat instance like object in allocate_for_instance

The allocate_for_instance method gets an instance object from the
compute manager so treat it like an object by using dot notation.

Updates the existing unit tests to use an instance object.

Part of blueprint compute-manager-objects-juno

Change-Id: Ia9305a67d1b9bd8601443da3288f710ab02b3f37
Merge "nova-network: treat instance like object in allocate_for_instance"
Merge "neutronv2: treat instance like object in allocate_for_instance"
Merge "Adds tests for Hyper-V VM Utils"