Split parameters schema and descriptions into single files
This merge request
- adds a script to split the long parameter files (e..g, Sites.yml) into one file per parameter
- adds base_schema_version and base_schema descriptor
No change in the test of the parameter schema description! So please review mostly the outcome in the parameter_schemas directory. Do not look in all files in parameter_schemas, just browse through a couple of ones and confirm that this is nice.
Notes:
- we probably do that only once, so a quick look into scripts/split_parameter_files.py should be enough.
- combine files (e.g., Sites.yml) will be deleted after we have agreed on this approach (we don't want to have duplicated code)
Will see if this stays or or is moved into the workflows/schemas repository.