Add new node asset scripts for geometry and shader operations

- Implemented `build_mesh_plane.py` to create a geometry node group for mesh planes with customizable parameters.
- Created `build_shadeless.py` for a shader node group that displays color without scene lighting while preserving shadows and reflections.
- Added `validate.py` to validate the integrity of the newly created node groups and their inputs.
- Introduced `validate_cutout.py` to ensure the functionality of cutout node groups and their dependencies.
- Developed `validate_mesh_plane.py` to test the mesh plane creation and its modifier settings.

src/anyimage/__init__.py

@@ -1,17 +1,17 @@
 import bpy
 
-from . import clipboard_image
-from .clipboard_image import CLASSES as CLIPBOARD_CLASSES
+from .operators import clipboard_image
+from .operators.clipboard_image import CLASSES as CLIPBOARD_CLASSES
 from .menu import AnyImageImageMenu, draw_image_context_menu
 from .operators import CLASSES as OPERATOR_CLASSES
-from .operators.cutout import CutoutTool
-from .operators.image_edit import (
+from .operators.cutout_tool import CutoutTool
+from .operators.image_tool import (
     ImageBoxTool,
     ImageLassoTool,
     ImageLineTool,
-    ImagePerspectiveTool,
     ImagePolylineTool,
 )
+from .operators.perspective_tool import ImagePerspectiveTool
 from .panel import (
     Ben2RemovalDebugPanel,
     Da3OutputDebugPanel,