default python apps: use super.on_enter/on_exit reliably

python_payload/apps/audio_passthrough/__init__.py

python_payload/apps/gay_drums/__init__.py

python_payload/apps/harmonic_demo/__init__.py

python_payload/apps/melodic_demo/__init__.py

python_payload/apps/nick/__init__.py

python_payload/apps/otamatone/__init__.py

python_payload/apps/shoegaze/__init__.py

python_payload/apps/tiny_sampler/__init__.py

python_payload/apps/w1f1/__init__.py

python_payload/apps/wurzelitzer/__init__.py