Add migrations, update seeding, and modify images

This commit includes multiple migrations for the Entity Framework Core application in the `EdufyAPI` namespace. Key changes involve:

- Initial database schema setup with tables for `Certificate`, `Course`, `Enrollment`, `Lesson`, and `Progress`.
- Addition of new properties and columns, including `Category` and `Level` in the `Courses` table.
- Updates to data seeding for courses, instructors, lessons, and quizzes, reflecting new identifiers and descriptions.
- Removal of the `NumberOfStudentsEnrolled` column from the `Courses` table.
- Significant updates to image files, including the addition of new binary data for several JPEG images, indicating modifications or replacements.

Author: Abdelrahman984