Enhance ACwater output

This adds some additional layers computed in POLYMER AC to the output of EnPT.

Tasks to be done:

• add additional parameters to the EnPT frontend to activate/deactivate the additional layers
  • adapt config files: config.py, options_default.json, options_schema.py
  • adapt command line argument parser(enpt_cli.py)
  • adapt GUI (enpt_enmapboxapp repository, here)
• pass the new config parameters through to the atmospheric correction submodule
• include new parameters in the call of ACwater
• add additional output layers of ACwater to the EnPT-internal data model
• adapt EnPT output writer to include the new output layers
• write a software test that covers the new optional parameters (some include it here)
• update the documentation and include the new ACwater output layers there (algorithm_descriptions.rst, probably about.rst, README.rst and maybe also something in tutorial.rst)
• test and validate the outputs
• add a version pinning for ACwater to avoid EnPT calls an old version of ACwater which does not implement the new layers yet (installation.rst)
• add @leonardo.alvarado in AUTHORS.rst and setup.py and make sure the existing ICLA/CCLA covers him
• update HISTORY.rst