Fix broken file ending from last commit
Reduce `HEIGHT_SENSOR_MAX_LOOPS` from 100 to 50
This seems to be enough for the sensor to write its data to the register.
Maybe this fix some height issues.
Add new event `EVENT_SENSOR_SWITCH_R`
This event is triggered when the token leaves the switch's lightbarrier.
The FSM now listen on this additional event from `b1_metal_detection`. The reaction
to the event is handled in `b1_metal_detection::dispatched_event_sensor_switch_rising`,
which closes the switch. `dispatcher_test` has beed adapted to the new state.
Also cleaned the FSM and `token` code. (This requires some more work)