Adds networking-hyperv cherry-picks
Adds networking-hyperv cherry-picks

Commit: https://review.openstack.org/#/c/264939
Refactors disconnect_switch_port, leading to fewer exceptions when ports are removed.

Commit: https://review.openstack.org/#/c/265728
Verifies that the VLAN tag was properly added.
cloudbase/hyperv-compute-ci,costingalan/hyperv-compute-ci,rbuzatu90/hyperv-compute-ci,rbuzatu90/hyperv-compute-ci,costingalan/hyperv-compute-ci,cloudbase/hyperv-compute-ci