Use 80-bit commands for tilt and stop + fix in somfy_frame_t::copy

[perfrankling]

For motors that tilt quickly, it is necessary to use the 80-bit StepUp, StepDown and stop commands to avoid the shade accidentally being sent to the my position. The PR implements this if 80-bit frames are used. Also corrected a missing copy of stepSize in somfy_frame_t::copy