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/test_preferences.py

@@ -439,6 +439,7 @@ class PreferencesTest(BlenderTestCase):
             type="EMPTY",
             empty_display_type="IMAGE",
             data=source_image,
+            image_user=None,
         )
         context = SimpleNamespace(
             object=source_object,
@@ -457,8 +458,8 @@ class PreferencesTest(BlenderTestCase):
                 return_value=1024,
             ),
             patch.object(
-                self.upscale,
-                "prepare_image_input",
+                self.upscale.ImageEditTarget,
+                "prepare",
                 return_value=(Path("input.png"), False),
             ),
             patch.object(