Refactor geometry node groups for image depth processing

- Introduced new utility functions in common nodes for evaluating fields and capturing attributes.
- Simplified volume field calculations in image depth cutout and panorama groups by utilizing new utility functions.
- Enhanced readability and maintainability of the image depth cutout and panorama node groups by removing redundant code and improving function usage.
- Adjusted default values for thickness and depth scale in image relief plane group for better user experience.
- Improved handling of geometry attributes and connections in image depth plane group to streamline processing.

tests/anyimage/operators/test_plane_objects.py

@@ -197,6 +197,9 @@ def test_relief_plane_builds_a_fixed_base_terrain_block():
     assert result.modifiers[0].node_group.name == "O Image Relief Plane"
     modifier = result.modifiers[0]
     group = modifier.node_group
+    for name in ("Thickness", "Depth Scale"):
+        identifier = object_data.modifier_input_identifier(group, name)
+        assert modifier[identifier] == 0.5
 
     def set_input(name, value):
         object_data.set_modifier_input(
@@ -262,3 +265,5 @@ def test_relief_plane_builds_a_fixed_base_terrain_block():
     set_input("Reference Depth", 1.2)
     sheet = _evaluated_positions(result)
     assert np.allclose(sheet[:, 2], 0.2, atol=1e-5)
+    set_input("Reference Depth", 0.8)
+    assert np.allclose(_evaluated_positions(result)[:, 2], 0.0, atol=1e-5)