Refactor and enhance geometry node groups for depth plane and material layers

- Updated the depth plane node group to load from an asset and simplified the interface.
- Created a new build script for depth plane geometry nodes.
- Introduced material layer groups for image and depth materials with appropriate sockets.
- Added functionality to connect balloon normal scale to the image material.
- Enhanced tests to validate the new node groups and their connections.
- Ensured that production code does not create node groups directly.

docs/reference/features.md

@@ -21,7 +21,7 @@
 
 ### Plane
 
-普通 Plane 使用内置 `O Mesh Plane` Geometry Nodes，提供 Subdivide、Thickness 和 Material。Depth Plane 使用运行时生成的 `O Image Depth Plane`，增加 Depth Amount 与内部 Depth Image。
+普通 Plane 使用资产中的 `O Mesh Plane` Geometry Nodes，提供 Subdivide、Thickness 和 Material。Depth Plane 使用同一资产文件中的 `O Image Depth Plane`，增加 Depth Amount 与内部 Depth Image。
 
 ### Cutout Shape