Add FOLIO info to Created_By value in exported files

Currently, the Created_By field in counter reports exported from FOLIO holds the value originally provided by the SUSHI provider.

But as in most export cases (csv, xlsx format, multiple months, ...) the data is transformed by the eUsage app, the field value should be enhanced by this information to make it possible for useres to distinguish between files downloaded directly from the provider's websites and fiels harvested and downloaded via FOLIO.

The new value should be

"Created_By": [platform] via FOLIO eUsage app