Add wait time for system to settle after ramping

[jusack]

During the control measurements (at least the version in JA/field-control) we have a time constant that determines when we assume the field to be stable after the ramping finished and only use the data after that. This was necessary to achieve stable control results.

However, we don't have a parameter like this during the measurement, meaning that the first periods of the data might not be accurate.

In our 1D-MPS this was approximately 1ms