Add reusable local HTTP job service for Blender add-ons

- Implement JobClient for handling HTTP requests to the JobServer.
- Create ModalJobOperatorBase for managing Blender job lifecycle.
- Introduce JobContext and JobServer for job management and state handling.
- Add ServiceConnection and ServiceController for managing service processes.
- Implement job submission, cancellation, and resource management endpoints in the server.
- Ensure proper error handling and job state updates throughout the service.

tests/test_image_depth.py

@@ -26,7 +26,11 @@ def load_image_depth():
     with patch.dict(sys.modules, {"bpy": fake_bpy}):
         specification = importlib.util.spec_from_file_location(
             "snapform_image_depth_test",
-            PROJECT_ROOT / "src" / "snapform" / "image_depth.py",
+            PROJECT_ROOT
+            / "src"
+            / "snapform"
+            / "blender"
+            / "depth_plane.py",
         )
         module = importlib.util.module_from_spec(specification)
         specification.loader.exec_module(module)