Resolve "Selecting exam lab when creating a lab, does not imply sign off intervals"

What does this mr do?

It adds a javascript snippet that makes the exam lab checkbox dependent on the sign off interval checkbox.

Actions taken to fix bug

Whenever exam lab is checked, sign off intervals is checked as well. The inverse, when sign off intervals gets unchecked, will uncheck exam lab as well. This way there is no way an exam lab without sign off intervals can be created.

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made and the bug I fixed.
• A test was created to test the bug.
• I have updated the documentation accordingly.
• I adhere to the style guide.

Closes #319 (closed)