ui(dropdown menu): Added DropdownMenu component in ui-next (#4387)

platform/ui-next/src/components/Dialog/index.ts

@@ -1,3 +1,14 @@
-import * as DialogComponents from './Dialog';
+import { Dialog, DialogPortal, DialogOverlay, DialogTrigger, DialogClose, DialogContent, DialogHeader, DialogFooter, DialogTitle, DialogDescription } from './Dialog';
 
-export default DialogComponents;
+export {
+  Dialog,
+  DialogPortal,
+  DialogOverlay,
+  DialogTrigger,
+  DialogClose,
+  DialogContent,
+  DialogHeader,
+  DialogFooter,
+  DialogTitle,
+  DialogDescription,
+};