fix: vue nodes preview node to match lg and add node when clicked (#7146)

## Summary

Make the preview node match recent LGraphNode.vue look. Also add support
to click from search.

## Changes

- **What**: NodeSearchBox.vue, LGraphNodePreview.vue, nodeDefStore.ts

## Screenshots (if applicable)


https://github.com/user-attachments/assets/ed46d641-66bf-4e23-a207-9102609a7a4a


┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7146-fix-vue-nodes-preview-node-to-match-lg-and-add-node-when-clicked-2bf6d73d3650814383b2c786e2ab4d02)
by [Unito](https://www.unito.io)

src/components/searchbox/NodeSearchBox.vue

@@ -3,11 +3,11 @@
     class="comfy-vue-node-search-container flex w-full min-w-96 items-center justify-center"
   >
     <div
-      v-if="enableNodePreview"
-      class="comfy-vue-node-preview-container absolute top-[50px] left-[-350px]"
+      v-if="enableNodePreview && hoveredSuggestion"
+      class="comfy-vue-node-preview-container absolute top-[50px] left-[-375px] z-50 cursor-pointer"
+      @mousedown.stop="onAddNode(hoveredSuggestion!)"
     >
       <NodePreview
-        v-if="hoveredSuggestion"
         :key="hoveredSuggestion?.name || ''"
         :node-def="hoveredSuggestion"
       />