Testing recipe_ref_trend_regions with CMIP7.

[katjaweigel]

Is your feature request related to a problem? Please describe.
REF recipes need to work with CMIP7 data.

Would you be able to help out?
I plan to test, if this recipe needs changes today/tomorrow, but I need to get the necessary CMIP7 dummy data first. It contains a time period, which should be potentially be updates. At the moment 1980-2009; CMIP6 recent past baseline would be 1995-2014; CMIP7 probably 2002-2021.

[katjaweigel]

The recipe uses several variables, therefor the branding suffix cannot be given for the (CMIP7) data set, because it can differ (tas: tavg_h2m_hxy_u, pr: tavg_u_hxy_u). It works to give it for each variable (is ignored in case of OBS/ native6) but this requires to change the recipe. Is that the right way to handle it? Would be problematic, if the branding suffix could differ for the same variable for different CMIP7 data sets?

[katjaweigel]

Else it works for tas and pr, for the other variables I need simulated CMIP7 variables first