3dgs & ply support (#7602)

## Summary

integrated sparkjs https://sparkjs.dev/, built by [world labs
](https://www.worldlabs.ai/) to support 3dgs.

- Add 3D Gaussian Splatting (3DGS) support using @sparkjsdev/spark
library
- Add PLY file format support with multiple rendering engines
- Support new file formats: `.ply`, `.spz`, `.splat`, `.ksplat`
- Add PLY Engine setting with three options: `threejs` (mesh), `fastply`
(optimized ASCII point clouds), `sparkjs` (3DGS)
- Add `FastPLYLoader` for 4-5x faster ASCII PLY parsing
- Add `original(Advanced)` material mode for point cloud rendering with
THREE.Points

3dgs generated by https://marble.worldlabs.ai/

test ply file from:
1. made by https://github.com/PozzettiAndrea/ComfyUI-DepthAnythingV3
2. threejs offically repo

## Screenshots


https://github.com/user-attachments/assets/44e64d3e-b58d-4341-9a70-a9aa64801220



https://github.com/user-attachments/assets/76b0dfba-0c12-4f64-91cb-bfc5d672294d



https://github.com/user-attachments/assets/2a8bfe81-1fb2-44c4-8787-dff325369c61



https://github.com/user-attachments/assets/e4beecee-d7a2-40c9-97f7-79b09c60312d

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7602-3dgs-ply-support-2cd6d73d3650814098fcea86cfaf747d)
by [Unito](https://www.unito.io)

package.json

@@ -146,6 +146,7 @@
     "@primevue/icons": "catalog:",
     "@primevue/themes": "catalog:",
     "@sentry/vue": "catalog:",
+    "@sparkjsdev/spark": "catalog:",
     "@tiptap/core": "^2.10.4",
     "@tiptap/extension-link": "^2.10.4",
     "@tiptap/extension-table": "^2.10.4",