GUI: peak should be discarded *during* integration rather than before

There are a few controls on SubframeIntegrate that instantly discard some peaks, namely "Remove overlaps" and "Remove masked peaks". This does not make sense since the these peaks may be valid on reintegration with different parameters, but are never reselected.

This is important because the integration region type and extents will affect both of these functionalities: for example, switching to a fixed integration region will probably result in fewer overlapping peak regions, and fewer peaks intersecting masked regions.