Feature/add toa ref transformer
This branch adds the TOA reflectance processor (processors.radiometric_transform.Radiometric_Transformer).
Additionally, the development of the TOARef processor required to add the following new features:
- earth-sun-distance lookup table + reader
- spectral response functions for EnMAP (model.srf.SRF)
- solar irradiance lookup table + reader
- computation of solar irradiance per band
- config module (options.config)
- default config JSON file
- default config schema (validator)
- command line argument parser (enpt_cli.py)
- EnPT controller
- many tests
The CI system had to be fixed.