Port Thru.de harvester to Rust to drop the SubmitText API.

This is the last harvester which needs to be ported to reduce the external harvester API to its bare minimum, i.e. the FetchText and WriteDataset messages.

It also gives us the opportunity to revamp the harvester to make use of the SQLite database containing all of the PRTR data which should greatly improve the efficiency of the harvester.

This does not work because the ID used by the export and by the website do not match. Nevertheless we can greatly improve the speed of the harvester by relying on the "Emissionen kompakt" section instead of the "Datensuche".