feat: Modal + ViewportDownloadForm

extensions/cornerstone/src/CornerstoneViewportDownloadForm.js

@@ -145,8 +145,4 @@ CornerstoneViewportDownloadForm.propTypes = {
   activeViewportIndex: PropTypes.number.isRequired,
 };
 
-// export default CornerstoneViewportDownloadForm;
-
-export default function HelloWorld() {
-  return <div>Hello World</div>;
-}
+export default CornerstoneViewportDownloadForm;