Refactor Cutout Tool to Use World Space Edge Length

- Replaced the Mesh Detail parameter with a new Edge Length property to define cutout sampling in physical units.
- Introduced Minimum Relative Edge Length preference to control effective spacing based on the bounding box of the cutout content.
- Updated tests to validate the new edge length functionality and ensure consistent behavior across different resolutions and canvas sizes.
- Removed deprecated parameters and adjusted related properties to align with the new edge length implementation.
- Enhanced geometry sampling logic to utilize effective world spacing for both standard and fine outline modes.

tests/anyimage/common/test_image_materials.py

@@ -92,7 +92,7 @@ def test_cutout_material_uses_ior_1_2():
     source.empty_display_size = 2.0
     bpy.context.collection.objects.link(source)
 
-    result = _create_cutout_shape(source, "FLAT", 8)
+    result = _create_cutout_shape(source, "FLAT", 0.1)
 
     shader = next(
         node