Add tests for clipboard image functionality and mesh plane asset creation

- Implemented a comprehensive test suite for the clipboard image module, covering various functionalities including operator registration, context handling, and image processing.
- Created a new mesh plane asset with customizable parameters and integrated it into the geometry node system.
- Developed a validation script to ensure the correct behavior of the mesh plane asset, including input handling and output verification.

tools/build_geometry_nodes_asset.py

@@ -2,6 +2,8 @@ from pathlib import Path
 
 import bpy
 
+from mesh_plane_asset import build_mesh_plane_group
+
 
 GROUP_NAME = "O DA3 Surface"
 MOGE_SURFACE_GROUP_NAME = "O MoGe2 Surface"
@@ -1436,6 +1438,7 @@ def main():
         discontinuity_default=50.0,
     )
     configure_moge_surface_group(moge_surface_group)
+    build_mesh_plane_group()
     build_depth_plane_group()
     build_moge_depth_plane_group()
     build_shadeless_group()