Add update to aircraft pairing to NaN the extrapolated values needed for met sondes with WRF-Chem

[rschwant]

Right now the extrapolated values use nearest neighbor extrapolation in the vertical because mostly aircraft doesn't fly that high. However, this is a problem for sonde data that gets above the model type for regional models like WRF-Chem. So we need an option in the yaml file to NaN the extrapolated values. I would just NaN both ends for now and we can play around with more complicated only NaNing near surface or top of the atmosphere later.