Adds proper error return to stuff involving upload links

src/schema.gql

@@ -458,9 +458,15 @@ input CreateBucketSetInput {
 }
 
 type GetUploadLinkReturn {
+  value: UploadLinkGetUploadLinkErrors!
+  stream: UploadStreamGQL
+}
+
+union UploadLinkGetUploadLinkErrors = UploadLink | GetUploadLinkErrors
+
+type UploadLink {
   uploadUrl: String!
   headers: [Header]!
-  uploadCompletionCursor: Int
 }
 
 type Header {
@@ -468,6 +474,38 @@ type Header {
   value: String!
 }
 
+type GetUploadLinkErrors {
+  error: MustHaveSetForUploadLinkErrSegmentAlreadyUploadedErrProcessingFailedErrNoInitForChunkedUploadErrTooManyProfileImageUploadsErr!
+}
+
+union MustHaveSetForUploadLinkErrSegmentAlreadyUploadedErrProcessingFailedErrNoInitForChunkedUploadErrTooManyProfileImageUploadsErr =
+    MustHaveSetForUploadLinkErr
+  | SegmentAlreadyUploadedErr
+  | ProcessingFailedErr
+  | NoInitForChunkedUploadErr
+  | TooManyProfileImageUploadsErr
+
+type MustHaveSetForUploadLinkErr {
+  resolution: Boolean
+  framesPerSecond: Boolean
+}
+
+type SegmentAlreadyUploadedErr {
+  segmentId: Int!
+}
+
+type ProcessingFailedErr {
+  processing: VideoProcessingGQL!
+}
+
+type NoInitForChunkedUploadErr {
+  segmentType: StreamSegmentTypeEnum!
+}
+
+type TooManyProfileImageUploadsErr {
+  linksRequested: Int!
+}
+
 type CreateUploadStreamReturn {
   videoId: Int!
 }