This commit provides a few fixes for quiz feature:
* fix amount of karma won by the user in a quiz;
* correctly display the fact that a subquiz was completed by the user instead
of just looking like a non-completed quiz;
* going on a previously completed quiz, good answers are hightlighted and
inputs disabled;
* effectively put the quiz in readonly mode if not a channel member.
Commit linked to task ID 1941250 and PR #31977
qmo-odoo
258a1e41b0