search: added graphql api to return repository list with latest tag

pkg/extensions/search/schema.graphql

@@ -35,12 +35,25 @@ type ImgResultForDigest {
 
 type TagInfo {
      Name: String
+     Digest: String
      Timestamp: Time
 }
 
+type ImageInfo {
+     Name: String
+     Latest: String
+     LastUpdated: Time
+     Description: String
+     Licenses: String
+     Vendor: String
+     Size: String
+     Labels: String
+}
+
 type Query {
   CVEListForImage(image: String!) :CVEResultForImage 
   ImageListForCVE(id: String!) :[ImgResultForCVE]
   ImageListWithCVEFixed(id: String!, image: String!) :ImgResultForFixedCVE
   ImageListForDigest(id: String!) :[ImgResultForDigest]
-}
+  ImageListWithLatestTag:[ImageInfo]
+}