Include spherical ice-crystal optical properties in ga9 spectral files

Optical properties for spherical ice-crystals can be generated in the existing examples/ice_crystals/run_2022 script. Here these are added to the standard ga9 and ga9_ref files for research use.

Further optical properties for spherical droplets are also added to the ga9_ref spectral files which make use of refractive index data extended into the far-UV and far-IR.