feat(editor): drag handle widget extension (#11962)

Closes: BS-3220

blocksuite/affine/widgets/drag-handle/package.json

@@ -37,7 +37,8 @@
   },
   "exports": {
     ".": "./src/index.ts",
-    "./effects": "./src/effects.ts"
+    "./effects": "./src/effects.ts",
+    "./view": "./src/view.ts"
   },
   "files": [
     "src",