Implement DWS measurement noise

!51 (merged) implemented angular jitters for SC and MOSAs, as well as noiseless DWS measurements.

We should implement DWS measurement noise, given as a white noise at 7 \times 10^{-8} / 335 rad/sqrt(Hz). Because we implement DWS measurements in angular velocity (rad/s), this becomes a violet noise at 2 \pi f \times 7 \times 10^{-8} / 335 rad/s/sqrt(Hz).