feat: Implement depth cutout symmetry and associated functionalities

- Introduced a new proposal for depth cutout symmetry, allowing for the reuse of depth replacement and geometry operations.
- Added requirements for maintaining default thickness values for cutout nodes and ensuring proper initialization during object creation.
- Enhanced symmetry node to handle existing geometry, including alignment, mirroring, and boundary filling.
- Implemented fill smoothing to control the geometry of generated walls while preserving original surfaces.
- Created tests to validate the functionality of the new symmetry features against baseline geometry.
- Updated existing assets and node groups to support the new symmetry capabilities without introducing additional dependencies.

tests/tools/nodes/test_cutouts.py

@@ -13,7 +13,7 @@ from anyimage.common.object import modifier_input_identifier, set_modifier_input
 
 
 @pytest.mark.parametrize("source", ("definition", "asset"))
-@pytest.mark.parametrize("shape", ("SOLID", "DEPTH_SOLID", "DEPTH_SYMMETRY"))
+@pytest.mark.parametrize("shape", ("SOLID", "DEPTH_SOLID"))
 def test_depth_axis_is_visible_in_options(shape, source):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     group = CUTOUT_BUILDERS[shape]() if source == "definition" else load_cutout_node_group(shape)