Resolve "The 2FA exercise doesn't work anymore on the LMS"

The backstory for this MR can be found in #66 (closed) but I'll summarize it:

The "javascript submit and grading" or something problems do not work anymore with newer versions of open edx deployed with Tutor. they changed it to improve security. The submit buttons were always optional, and rarely used by people, so we took them out. That is what I did in this MR

This MR addresses #66 (closed), but it does not close it because we still need to change all the courses after this MR has been merged.