added quiz feature

[Inshamhaque]

solves issue #55 . Kindly update if any thing else is required.

Summary by CodeRabbit

• New Features

  • Introduced an interactive quiz module with live quiz sessions featuring a countdown timer and real-time feedback.
  • Added a dedicated section on the homepage presenting available quizzes with navigation controls.
  • Implemented a dynamic leaderboard to display user rankings and results.
  • Enhanced quiz management capabilities with new models for quizzes, questions, options, and submissions.
  • Integrated user authentication checks to tailor actions and improve navigation during quiz participation.
  • Added new templates for displaying live quizzes and leaderboards.
  • New utility function to validate that quizzes have questions.

• Bug Fixes

  • Improved error handling for non-existent quizzes and user submissions.

• Tests

  • Introduced comprehensive unit tests for quiz-related models, views, and admin functionalities.