Refactor/code-reivew (#7893)

## Summary

<!-- One sentence describing what changed and why. -->
https://github.com/Comfy-Org/ComfyUI_frontend/pull/7871
https://github.com/Comfy-Org/ComfyUI_frontend/pull/7858
I refactored the code based on the reviews I received on those two PRs.

## Changes

- **What**: 

1. Updated IconGroup to address the backgroundClass handling.
2. Replaced text-gold-600 with a semantic color token.
3. Replaced PrimeVue Icon with a lucide icon.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7893-Refactor-code-reivew-2e26d73d365081e68a44e89ed1163062)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: GitHub Action <action@github.com>

src/components/dialog/content/MissingNodesHeader.vue

@@ -1,7 +1,7 @@
 <template>
   <div class="flex w-full items-center justify-between p-4">
     <div class="flex items-center gap-2">
-      <i class="icon-[lucide--triangle-alert] text-gold-600"></i>
+      <i class="icon-[lucide--triangle-alert] text-warning-background"></i>
       <p class="m-0 text-sm">
         {{
           isCloud