Use proxy layer in identity_user_info

- Changes the module to get user through proxy layer
- Adds a role to test the module
- Renames the return value to drop openstack_ prefix

Change-Id: I99e98a529ce74ff2ca77a67d09f188228e6a0e37

ci/roles/identity_user_info/defaults/main.yml

@@ -0,0 +1,11 @@
+os_expected_user_info_fields:
+  - default_project_id
+  - description
+  - domain_id
+  - email
+  - id
+  - is_enabled
+  - links
+  - name
+  - password
+  - password_expires_at