Define v1 image_members_client as library

Image v1 API's image_members_client has good interfaces now,
then this patch makes the client as a library.

Partially implements blueprint consistent-service-method-names

Change-Id: I51af23c1249a10c8d4ddea99b28e61dccb5f38c2
diff --git a/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml b/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml
index faae7d0..90a5056 100644
--- a/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml
+++ b/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml
@@ -6,6 +6,7 @@
     so the other projects can use these modules as stable libraries
     without any maintenance changes.
 
+      * image_members_client(v1)
       * image_members_client(v2)
       * images_client(v2)
       * namespaces_client(v2)