Adds proper error return to stuff involving upload links

src/operations/user.gql

@@ -1,9 +1,20 @@
 mutation getProfileImageUploadLink($fileExt: String = ".png") {
   getProfileImageUploadLink(fileExt: $fileExt) {
-    uploadUrl
-    headers {
-      key
-      value
+    value {
+      ... on UploadLink {
+        uploadUrl
+        headers {
+          key
+          value
+        }
+      }
+      ... on GetUploadLinkErrors {
+        error {
+          ... on TooManyProfileImageUploadsErr {
+            linksRequested
+          }
+        }
+      }
     }
   }
 }