Define v3 endpoints_client as library

Migrate v3 API endpoints_client to tempest.lib

Partially implements blueprint consistent-service-method-names

Change-Id: Ic6836aef3400d5b1d14320896ae3a3f4f1eaa450
diff --git a/releasenotes/notes/identity-clients-as-library-e663c6132fcac6c2.yaml b/releasenotes/notes/identity-clients-as-library-e663c6132fcac6c2.yaml
index f9173a0..1f3d930 100644
--- a/releasenotes/notes/identity-clients-as-library-e663c6132fcac6c2.yaml
+++ b/releasenotes/notes/identity-clients-as-library-e663c6132fcac6c2.yaml
@@ -7,6 +7,7 @@
     any maintenance changes.
 
       * endpoints_client(v2)
+      * endpoints_client(v3)
       * roles_client(v2)
       * services_client(v2)
       * tenants_client(v2)