Context:
See OPT-3309

AT's:

• the CSV export uses the report data to extract the excluded columns
• the rest API documentation is adjusted so the excluded columns are not needed as request parameters any longer
• there's an additional process in the data generation that contains 100 variables so be able to manually test those cases
• the name of the process indicates that it has a lot of variables
• the process is added to the front-end and stage data set