Ability for an Admin deactivate SEB templates despite its usage in existing quizzes

If a course containing a quiz using a SEB template is restored in a new moodle site that SEB template will be added to the system's SEB templates and becomes available to any new quizzes added from now on. Because of the way SEB works, that template is only useful for a given SEB version. Once an institution/student upgrades to a new SEB version that available template will no longer allow the student.
As an Admin, I should be able to hide/deactivate that template in the system so that an editing teacher can no longer select it for a new quiz.

Discussion: https://moodle.org/mod/forum/discuss.php?d=441090