Add new tests and functionality for image processing and geometry handling

- Introduced color_image.py for preparing standalone color images for tests.
- Added hdr_image.py to create HDR textures for testing.
- Implemented test_image_depth_panorama.py to evaluate panorama topology, UVs, and depth discontinuities.
- Created test_shadeless.py to validate the opacity and HDR color endpoints of the Shadeless group.
- Developed moge3_export.py for exporting dynamic MoGe-3 backbone and ONNX graphs.
- Added material.py to inherit material slots onto generated geometry.
- Built image_depth_panorama.py to construct a quad panorama with depth separation and sampling.

tests/tools/nodes/test_saved_layout.py

@@ -22,7 +22,7 @@ class NodeAssetsTest(unittest.TestCase):
             for group in target.node_groups
             if group.bl_idname == "GeometryNodeTree"
         ]
-        self.assertEqual(len(groups), 6)
+        self.assertEqual(len(groups), 7)
         for group in groups:
             validate_node_structure(group)
             positions = {node.name: tuple(node.location) for node in group.nodes