Automatically remove digital filter distortion at the end of the FID

When applying a digital filter correction on an FID (e.g. Bruker data), this also affects the end of the FID. Normally I would always remove this distortion at the end of the FID, either by removing those points or by applying a strong apodization. It would be great if ssNake could remove (or replace by zeros) these points automatically.

Image: end of an FID after digital filter correction

Related: #184 (which is about doing the digital filter correction automatically, and adding a setting to do so)