Add timers for state `b1_token_too_small`
This introduce the new state `b1_token_too_small_seg2_ok`, this state is entered
when the `EVENT_SEG2_HAS_TO_EXPIRE` event is triggered. `b1_token_too_small_seg2_ok::dispatched_event_sensor_slide()`
now handles the good case. `b1_token_too_small::dispatched_event_sensor_slide()` handles the too early case.
`b1_token_too_small_seg2_ok::dispatched_event_seg2_too_late()` handles the too late case.