Modifications

• Add computation of Psfao gradients
• Psfao centering (motivated by GalPak implementation):
  • Internally perform the subsampled data shift (previously left to user)
  • Odd array size centering on one pixel
• Add fixed_k keyword to ParametricPSFfromPSD to fix the size of arrays used internally in case of undersampling
• Add MUSE WFM instrument

Warning

Loss of compatibility on Psfao centering for undersampled data.