ImagesTable: add image name

If a user has specified an image name the name will appear. Otherwise
the image's UUID will appear.

The test needed to be modified to search for the compose in the store
with either the image name or the id

src/Components/ImagesTable/ImagesTable.js

@@ -91,7 +91,7 @@ class ImagesTable extends Component {
         let { composes } = this.props;
 
         const columns = [
-            'Image',
+            'Image name',
             'Created',
             'Release',
             'Target',
@@ -107,7 +107,7 @@ class ImagesTable extends Component {
             const compose = composes.byId[id];
             return {
                 cells: [
-                    id,
+                    compose.request.image_name || id,
                     this.timestampToDisplayString(compose.created_at),
                     { title: <Release release={ compose.request.distribution } /> },
                     { title: <Target