Submission Modal in Student Overvie needs clear way of closing
Summary
The modal that is displayed on smaller screen sizes to display the submission in the student overview need a clear way of closing. At the moment, the user has to click outside of the modal to close it.
Steps to reproduce
As a reviewer, go to Students and limit the browser size so that the side view disappears. Clicking a submission opens a modal that can only be closed by clicking outside of it.
What is the current bug behavior?
Modal can only be closed by clicking outside of it.
What is the expected correct behavior?
There should be a X button for that.