Be less strict with uploading scans from multiple exams
We've just ran an anonymous survey (see also #73) in parallel with an exam. For that we created 2 zesje exams. However when scanning some solutions got mixed up with the surveys. If this happens, zesje currently halts processing the scan.
On the other hand, I think that both:
- Continuing with the processing and ignoring extra pages
- Making a single upload form that determines the exam from the QR code right away
would make life easier, while not introducing dangerous failure modes.