search: graphql api to give detailed repo info

DetailedRepoInfo graphql api returns detailed repo info given repo name
repo contains its manifests info
Each manifest entry contains digest,signed, tag and layers info
Each layer info containes digest, size

Signed-off-by: Shivam Mishra <shimish2@cisco.com>

pkg/extensions/search/schema.graphql

@@ -50,10 +50,27 @@ type ImageInfo {
      Labels: String
 }
 
+type RepoInfo {
+     Manifests: [ManifestInfo]
+}
+
+type ManifestInfo {
+     Digest: String
+     Tag: String
+     IsSigned: Boolean
+     Layers: [LayerInfo]
+}
+
+type LayerInfo {
+     Size: String # Int64 is not supported.
+     Digest: String
+}
+
 type Query {
   CVEListForImage(image: String!) :CVEResultForImage 
   ImageListForCVE(id: String!) :[ImgResultForCVE]
   ImageListWithCVEFixed(id: String!, image: String!) :ImgResultForFixedCVE
   ImageListForDigest(id: String!) :[ImgResultForDigest]
   ImageListWithLatestTag:[ImageInfo]
+  ExpandedRepoInfo(repo: String!):RepoInfo
 }