[UI/UX] Quiz improvements #62

As a user, I want to which question has an answer selected and what the answer is when I navigate to it.

Acceptance criteria

Verify, consult and update before starting.

• When a question has an answer, the circle remains black with a white number.
• Current question has a bigger circle (black with a white number), so it is easier to tell where we are.
• Selected answer has similar styling to on hover, so it is easier to tell which answer was previously selected.
• "Question bubble" can be clicked. On click, it navigates to the selected question.

Additional notes