add support for RECOM ocean fluxes

Christopher Danek from Awi has provided one year of CO2 flux data from a historical run of the AWI-ESM model with the RECOM OBGC model.

Adding support for this dataset requires obtaining the proper grids/areas/masks.nc files so that oasis can generate the remapping weights. I have contacted Christopher and Jan Streffing from AWI to obtain them.

We should create a new config based on the carbon-tracker one but with a differnt ocean flux.

Example file for 2014 : /perm/de2d/post/recom/select/CO2f/awi-esm-1-1-lr_kh800_historical2_recom_select_CO2f_global_Jan-Dec_2014-2014_setgrid.nc