OHIF-285/OHIF-274: Fix default hanging of display sets into the ViewportGrid (#1917)

* OHIF-285/OHIF-274: Fix default hanging of display sets into the ViewportGrid

Co-authored-by: James A. Petts <jamesapetts@gmail.com>

extensions/default/src/DicomWebDataSource/wado/retrieveMetadata.js

@@ -29,9 +29,12 @@ async function RetrieveMetadata(
     studyInstanceUid,
     filters
   );
-  const studyMetadata = retrieveMetadataLoader.execLoad();
+  const { preLoadData, promises } = await retrieveMetadataLoader.execLoad();
 
-  return studyMetadata;
+  return {
+    seriesSummaryMetadata: preLoadData,
+    seriesPromises: promises,
+  };
 }
 
 export default RetrieveMetadata;