[DebugTargetPipeline] Add flow_debug function

src/polystar/target_pipeline/debug_pipeline.py

...target_pipeline/objects_detectors/objects_detector_abc.py

...star/target_pipeline/objects_detectors/robots_detector.py

src/polystar/target_pipeline/target_pipeline.py

src/polystar/utils/thread.py

src/research/scripts/demo_pipeline.py

src/research/scripts/demo_pipeline_camera.py