Enhance image editing tests and functionality

- Added parameterized tests for image edit replacement to ensure alpha mode preservation.
- Refactored existing tests to utilize new image editing methods and improve clarity.
- Introduced new tests for image target functionality, ensuring proper handling of shared textures and context.
- Updated various tests to validate alpha mode handling across different scenarios.
- Improved undo/redo functionality in image operators to maintain state consistency.
- Added support for texture node actions, enhancing integration with Blender's node system.
- Ensured that image properties are preserved during operations and that invalid contexts are handled gracefully.

tests/anyimage/operators/test_image_edit_integration.py

@@ -31,7 +31,7 @@ def test_image_edit_result_uses_complete_shared_source_name():
 
     assert shared.data == source_image
     assert source_image.alpha_mode == "STRAIGHT"
-    assert result_image.alpha_mode == "PREMUL"
+    assert result_image.alpha_mode == "STRAIGHT"
     assert source.use_empty_image_alpha
     assert source.data == result_image
     assert result_image.name == "Poster.png.001"
@@ -92,14 +92,14 @@ def test_mask_frame_mask_add_preserves_packed_hidden_rgb():
     )
     result = image_data.create_image_edit_result(source.data, framed, (4, 4))
     result = image_data.replace_empty_image(source, result)
-    assert result.alpha_mode == "PREMUL"
+    assert result.alpha_mode == "STRAIGHT"
     assert source.use_empty_image_alpha
     assert result.packed_file is not None
     packed = np.asarray(Image.open(BytesIO(result.packed_file.data)).convert("RGBA")) / 255.0
     np.testing.assert_allclose(packed[..., :3], expected[..., :3], atol=1 / 255)
     np.testing.assert_array_equal(packed[..., 3], 0)
     result.reload()
-    assert result.alpha_mode == "PREMUL"
+    assert result.alpha_mode == "STRAIGHT"
     operator.mode = "ADD"
     assert edit_mask.EditImageAlpha._apply_mask(
         operator, SimpleNamespace(), source, selection