Lecturer schould be able to un-queue students after accepting a queue request
# TODO
- Check if teacher has buttons after accepting a request and fix if not
# Summary
After a student booked a slot and the booking was approved, the booking should still be cancellable by the student (i think it is?), AND also the lecturer.
# Reasoning
We used the Queue to schedule oral exams. Some students got wet feet last minute, and sent a cancellation email to us. I would now want to cancel their appointment. But I cannot (?). So I need to send them a mail and tell them to please un-queue themselves?
# To fix
Reject button does not always show up for teachers
issue