Adds availability zone support for Nova V3 API

Adds support and tests for the os-availability-zones
extension for the Nova V3 API. Also implements
sorting for zone host display which was applied
to the v1_1 version, but not the v3 version in
I9ab25ef52d6d19b45a39f04cbcde864ee225b4cc

Partially implements blueprint v3-api

Change-Id: I8daa2503a2dc8767e9157bdfa6c9adaedfc8f3c0
Merge "Adds availability zone support for Nova V3 API"