Draft: Implement consideration of EnMAP spectral smile

A first implementation of EnMAP spectral smile consideration is pushed to this merge request. However, merging into master will not be performed before the implementation is tested with real coefficients. Currently, no instrument smile is indicated by zero-entries in the coefficients for each band. It was also decided to add a spectral smile correction after performing the atmospheric correction within SICOR, which will likewise be implemented after receiving real smile coefficients from instrument data.