Implement arrangement framework for node groups

- Introduced `frames.py` to manage field complex calculations and their arrangement within node groups.
- Added functionality to create and remove field frames based on node arrangements.
- Developed `passages.py` to find unobstructed paths for connections around calculation frames.
- Implemented `references.py` to route shared results on peripheral tracks, ensuring efficient distribution of outputs.
- Created `sections.py` to reserve space for field calculations adjacent to geometry consumers.
- Added `sources.py` to position shared calculation sources effectively beside their distribution channels.
- Enhanced outline smoothing with `outline_smoothing.py` to adapt camera depth along original outlines.

tests/tools/nodes/test_depth_strip_cleanup.py

@@ -134,7 +134,7 @@ def test_split_input_precedes_smooth_without_cleanup_switch(kind):
     split = inputs[names.index("Split Threshold")]
     assert split.parent == inputs[names.index("Smooth")].parent
     assert split.parent.name != "Options"
-    assert split.default_value == pytest.approx(0.1 if kind == "cutout" else 0)
+    assert split.default_value == pytest.approx(0.1)
     assert (split.min_value, split.max_value, split.subtype) == (0, 1, "FACTOR")
     assert "Remove Strip Faces" not in names
 
@@ -157,6 +157,7 @@ def test_strips_are_removed_before_projection_and_closed_thickness(kind):
     image.pixels.foreach_set(pixels.ravel())
     image.update()
     set_value("Depth Scale", 1.0)
+    set_value("Reference Depth", 11.0)
     assert len(evaluated(obj)[1]) == 8
     set_value("Split Threshold", 0.5)
     vertices, faces = evaluated(obj)