code improve for 3d node (#6403)

## Summary

code improve for 3d node

## Changes

1. remove custom css
2. use tailwind instead
3. bug fix for right click context menu

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6403-code-improve-for-3d-node-29c6d73d3650819fab26feabdaa21821)
by [Unito](https://www.unito.io)

src/components/load3d/Load3DScene.vue

@@ -1,5 +1,5 @@
 <template>
-  <div ref="container" class="comfy-load-3d relative h-full w-full">
+  <div ref="container" class="relative h-full w-full">
     <LoadingOverlay ref="loadingOverlayRef" />
   </div>
 </template>

src/components/load3d/Load3dViewerContent.vue

@@ -9,7 +9,7 @@
     <div ref="mainContentRef" class="relative flex-1">
       <div
         ref="containerRef"
-        class="comfy-load-3d-viewer absolute h-full w-full"
+        class="absolute h-full w-full"
         @resize="viewer.handleResize"
       />
     </div>