Use Senses class instead of scene to handle compasses, etc. at a later stage

doc/source/example/processing/apcv.py

doc/source/example/processing/contrast_weighted_nearness.py

doc/source/example/processing/michelson_contrast.py

doc/source/example/processing/pcv.py

doc/source/example/processing/skyline.py

doc/source/example/rendering/blenddemo_beesampling.py

doc/source/example/rendering/blenddemo_cyberbee.py

navipy/database/__init__.py

navipy/moving/agent.py

navipy/sensors/__init__.py

navipy/sensors/bee_sampling.py

navipy/sensors/renderer.py