Define v1 images_client as library

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

Partially implements blueprint consistent-service-method-names

Change-Id: I8a0346e5526bfb83e54e0184bbc34ad5195203c3
diff --git a/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml b/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml
index 90a5056..1fa4ddd 100644
--- a/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml
+++ b/releasenotes/notes/image-clients-as-library-86d17caa26ce3961.yaml
@@ -7,6 +7,7 @@
     without any maintenance changes.
 
       * image_members_client(v1)
+      * images_client(v1)
       * image_members_client(v2)
       * images_client(v2)
       * namespaces_client(v2)