Wash function for windscreen and rear window

The wash functions are available as of terminal 30B ON.

The washer pump is activated for the activation time. If the wash/wipe switch is operated for a very short time (less than 300 ms), only the windscreen washer pump is activated. If it is actuated for a longer period, the wiper is added with a delay. After the washer pump is switched off, the windscreen is wiped for 3 wipe cycles to wipe the windscreen dry.