Claim an exam PDF from the exam screen

This is a really minor nitpick, but it's currently quite tedious to do the admin flow of "upload PDF and cut it". It's because we have to Claim the exam between "upload" and "cut" to prevent race conditions from other admins who may see it in the mod queue.

The PDF upload dialogue redirects to the /exam/page, so the user flow involves using the breadcrumb menu to go back to the category to claim the exam then navigate back to start cutting it. Which is quite tedious and gets quite annoying when doing this operation many times.

It would be very helpful if there was a way to Claim an exam from within an exam screen, maybe another button in the side panel?

Alternatively, it could also be implemented by the "Add Cuts" button automatically claiming the exam (and disable the button if claimed by another person).