Allow multiple retakes of Quizzes Merged

It be helpful to have the ability to allow for a set number of Quiz retakes without having to be reopened by the teacher. For example, if I allow 1 retake, then if a student missing 1 item, but knows their mistake, they can go in and correct their mistake with me having to reopen the quiz.

The system would need to keep track of the initial score and the retake score(s).