several changes for co2box model in tests/ : use global (not hemispheric) co2 box model and deactivate co2 emissions in IFS_mock.py ; updates to convert-ece4pyreader-grids.sh

several changes for co2box model in sources/data-coupler/ : various bugfixes and more logging ; rename oasisIn to oasisOut ; allow option to accumulate and add fields (e.g. emissions) or only read field for first timestep (e.g. initial co2) ; add constants and named scale factors (e.g. co2_ppm_to_mass) ; use global (not hemispheric) co2 box model

basic refactoring with new OasisOutVar (handling update and send internally) and renaming DataCouplerVar class to FileInputVar

add DataCouplerCO2Box.py and associated namelist and namcouple, identical in functionality to DataCouplerAMIP.py

add support for co2 concentration and sending data from multiple variable to one oasis var (e.g. CO2-em-anthro and CO2-em-AIR-anthro)

See merge request rmarti1/python-amip-reader!4

refactor: Dynamic coupling fields

See merge request rmarti1/python-amip-reader!3

feat: Add MN4 compatibility and documentation

See merge request rmarti1/python-amip-reader!2