🐛 Fix quiz question pagination scroll and active item visibility

[b-l-i-n-d]

• Fixes the question pagination overflowing horizontally in the quiz learning area.
• Adds edge fade indicators on the pagination when items are scrollable.
• Auto-scrolls the pagination to keep the active question item in view.
• Adds a data-quiz-question-index attribute to pagination items for targeting.
• Keeps the currently active question visible when navigating between questions.