Give ordering for CSVs getting imported

[tienne-B]

To avoid CSVs referencing data that isn't yet imported (say Teams from an institution before the institution), there should be a order in which we import CSVs. This should be well specified within the CSV-Importers repo.

The fields available in each CSV should be recognized, and all field names should be selectable (like for file names) to match our mapping. With a select, readable names can be used, and localized.