refactor(editor): move file drop manager to components (#9264)

blocksuite/blocks/src/root-block/widgets/drag-handle/watchers/drag-event-watcher.ts

@@ -109,6 +109,12 @@ export class DragEventWatcher {
   };
 
   private readonly _dropHandler = (context: UIEventStateContext) => {
+    const raw = context.get('dndState').raw;
+    const fileLength = raw.dataTransfer?.files.length ?? 0;
+    // If drop files, should let file drop extension handle it
+    if (fileLength > 0) {
+      return;
+    }
     this._onDrop(context);
     this._std.selection.setGroup('gfx', []);
     this.widget.clearRaf();