enh: Add derivative computations for Triangle normal and area [PointSet]
enh: Add derivative computations for Triangle normal and area [PointSet]

stefanpsz/MIRTK,BioMedIA/MIRTK,schuhschuh/MIRTK,BioMedIA/MIRTK,BioMedIA/MIRTK,BioMedIA/MIRTK,schuhschuh/MIRTK,stefanpsz/MIRTK,schuhschuh/MIRTK,schuhschuh/MIRTK,stefanpsz/MIRTK,stefanpsz/MIRTK