feat: add TODO comment for icon finalization in QuestionList component

- Added a TODO comment indicating that the icon for the 'Pin on Image' quiz type is not final, to ensure future updates address this aspect.

Author: saadman30

assets/src/js/v3/entries/course-builder/components/curriculum/QuestionList.tsx

@@ -113,6 +113,7 @@ const questionTypeOptions: {
   {
     label: __('Pin on Image', 'tutor'),
     value: 'pin_image',
+    // TODO: icon is not final.
     icon: 'quizImageAnswer',
     isPro: true,
   },