Amend radiation budget recipe and diagnostic script on ESMValTool

[NParsonsMO]

Change the plots to take alias instead of dataset in diagnostic (python) file.

Also remove hardcoded dataset names from descriptions in recipe (YAML) file.

[NParsonsMO]

PR opened on ESMValTool:
ESMValGroup/ESMValTool#4292

I've requested Emma Hogan (@ehogan) as a reviewer.