feat: use custom @ import dialog (#8723)

[BS-1747](https://linear.app/affine-design/issue/BS-1747/[ui]-通过导入的ui还是旧的，需要更新)

packages/frontend/track/src/events.ts

@@ -273,7 +273,7 @@ const PageEvents = {
   doc: {
     editor: {
       slashMenu: ['linkDoc', 'createDoc', 'bookmark'],
-      atMenu: ['linkDoc'],
+      atMenu: ['linkDoc', 'import'],
       quickSearch: ['createDoc'],
       formatToolbar: ['bold'],
       pageRef: ['navigate'],