Wrong IMAS DD version in `STEP_SPP_001_EBCC_freeboundary.nc`

[timothy-nunn]

When running ncdump STEP_SPP_001_EBCC_freeboundary.nc | grep .data_dictionary I get the following output, implying that the data uses version 4.0.0 of the IMAS data dictionary:

:data_dictionary_version = "4.0.0" ;
        string ids_properties.version_put.data_dictionary ;
                string ids_properties.version_put.data_dictionary:_FillValue = "" ;
                ids_properties.version_put.data_dictionary:documentation = "Version of Data Dictionary used to PUT this IDS" ;
     ids_properties.version_put.data_dictionary = "4.0.0" ;
        string ids_properties.version_put.data_dictionary ;
                string ids_properties.version_put.data_dictionary:_FillValue = "" ;
                ids_properties.version_put.data_dictionary:documentation = "Version of Data Dictionary used to PUT this IDS" ;
     ids_properties.version_put.data_dictionary = "4.0.0" ;
        string ids_properties.version_put.data_dictionary ;
                string ids_properties.version_put.data_dictionary:_FillValue = "" ;
                ids_properties.version_put.data_dictionary:documentation = "Version of Data Dictionary used to PUT this IDS" ;
     ids_properties.version_put.data_dictionary = "4.0.0" ;

I believe this is wrong for two reasons:

1. @fcasson states in Update README.md #2 that the data dictionary version is 3.x
2. The equilibrium data is not consistent with COCOS 17 (which would be required for it to be IMAS DD version 4 https://imas-data-dictionary.readthedocs.io/en/latest/cocos.html#cocos)

[fcasson]

Definitely we use DD v3, I think it is 3.39. So this is a bug from the conversion process to NETCDF using imas-python - @theo-brown

[theo-brown]

Thanks @timothy-nunn for catching this, and thanks @fcasson for the ping. I'll have look this week.

My initial guess at what might have happened is that the IMAS-python convertor to netCDF did a partial translation to DDv4, as Francis suggested.