CMIP7 style sample data

[bouweandela]

We could reCMORize the current CMIP6 sample data by generalizing this code https://github.com/WCRP-CMIP/cmip7-cmor-tables/blob/main/Simple_recmorise_cmip6-cmip7.ipynb so it loops over all the CMIP6 sample data in this repository. That would allow testing the REF before real CMIP7 data is available and would give us a head start.

This code may be useful to https://github.com/CMIP-Data-Request/CMIP7_DReq_Software/blob/main/scripts/branding/generate_branded_names.py to retrieve the branded variable name.