Notification System

[pythonkumasi]

Implement notification system for reviews and deadlines.

Subtasks:

1. Create notification models
2. Set up email notifications
3. Implement in-app notifications
4. Add notification preferences
5. Create notification templates
6. Set up reminder system
7. Add notification history
8. Implement notification marking

Estimated Time Frame: 2 days

[Frederick-Teye]

Please, assign me this