Migrate V1 and V2 qos service to tempest lib

Split and migrate v1 and v2 API qos_client to tempest.lib.

Partially implements blueprint consistent-service-method-names
Change-Id: I14c3db7f1229a030a02f60f686826508afa01f61
diff --git a/releasenotes/notes/add-volume-clients-as-a-library-d05b6bc35e66c6ef.yaml b/releasenotes/notes/add-volume-clients-as-a-library-d05b6bc35e66c6ef.yaml
index 8125ab9..1ef2b0d 100644
--- a/releasenotes/notes/add-volume-clients-as-a-library-d05b6bc35e66c6ef.yaml
+++ b/releasenotes/notes/add-volume-clients-as-a-library-d05b6bc35e66c6ef.yaml
@@ -7,6 +7,8 @@
     any maintenance changes.
 
     * encryption_types_client (v1)
+    * qos_clients (v1)
+    * qos_clients (v2)
     * snapshots_client (v1)
     * snapshots_client (v2)