add averageDifficulty to aggregate operation

Reviewed-on: #212

src/operations/aggregate.gql

@@ -7,6 +7,7 @@ query GetAggregatedShotMetrics($aggregateInput: AggregateInputGQL!) {
     targetMetrics {
       count
       makePercentage
+      averageDifficulty
     }
   }
 }

src/operations/feed.gql

@@ -50,6 +50,7 @@ fragment VideoCardFields on VideoGQL {
     streamSegmentType
   }
   tableSize
+  pocketSize
   tags {
     tagClasses {
       name

src/operations/video.gql

@@ -211,13 +211,6 @@ query GetMedianRunForVideo($videoId: Int!) {
   }
 }
 
-query GetAverageDifficultyForVideo($videoId: Int!) {
-  getVideo(videoId: $videoId) {
-    id
-    averageDifficulty
-  }
-}
-
 fragment StreamWithEndFrames on UploadStreamGQL {
   id
   streamSegmentType