feat(quiz): enforce time limit and max attempt rules on quiz submission

[Ibinola]

📌 Pull Request Title

Description

This PR addresses #96 by enforcing quiz submission rules:

• ⛔ Rejects submissions if the user exceeds the allowed number of attempts.
• ⏱️ Rejects submissions made after the quiz time limit has passed.

The validation is handled in the submitQuizAttempt service logic.

Related Issues

Closes #96

Changes Made

• Added maxAttempts and timeLimit fields to the Quiz entity.
• Updated QuizAttempt entity to include startTime, endTime, and attemptCount.
• Enforced time limit and max attempt validation in submitQuizAttempt method.
• Updated the /quizzes/attempts/:id/submit endpoint to reject invalid submissions.
• Added utility method to validate quiz submission timing and attempt count.

How to Test

N/A

Screenshots (if applicable)

N/A

Checklist

• My code follows the project's coding style.
• I have tested these changes locally.
• Documentation has been updated where necessary.