Permit reading audience data during a quiz (2)

If a quiz is running, it is not possible to enter the "Edit participant" modal for the audience the quiz is running for. Although it is expected that it should not be possible to change the audience during a quiz, not being able to read the information is a problem. Especially for authenticated audiences, this means there is no way to request the token of a participant during a quiz, which opposed a problem during last year's LMS Diagnostic Test quiz.

Although the back-end already permits reading this data, the front-end needs some important changes to make this possible.

• React: In the DataTable component, make sure it is possible to disable options per option instead of all at once.
• React: In the AudienceParticipants component, make sure to enable all options unless a quiz is running, then disable the 'Delete' option.
• Thymeleaf: Make sure the "Edit participant" modal cannot be submitted while a quiz is running.