Updating external datasets from another form's submissions data from within a PostgreSQL database

[mathieubossaert]

I will first simply copy/adapt the push_json_media_to_central() function for csv files. I will try it by the end of the day and update the repo to add push_csv_media_to_central() function.
In a second time will probably add a generic function to upload csv or geojson or xml attachments that checks the file extension to adapt the Content-type Header.