feat: rename Vue-only widget label to Node 2.0 only (#8025)

## Summary

Add i18n key widgets.node2only and use it in litegraph widgets that only
support vueNodes mode.

## Screenshots (if applicable)
<img width="534" height="288" alt="image"
src="https://github.com/user-attachments/assets/e0987ec7-af09-4885-adf1-0c5cd6cba356"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8025-feat-rename-Vue-only-widget-label-to-Node-2-0-only-2e76d73d3650812cb7baf763440e2452)
by [Unito](https://www.unito.io)

src/locales/en/main.json

@@ -2083,6 +2083,7 @@
     "Set Group Nodes to Always": "Set Group Nodes to Always"
   },
   "widgets": {
+    "node2only": "Node 2.0 only",
     "selectModel": "Select model",
     "uploadSelect": {
       "placeholder": "Select...",