- Added functionality
- Add connection checks to `CreateUserSource`, `UpdateUserSource`, `GetUserSourceByID`, and `DeleteUserSource` functions.
- Introduce validation for empty and improperly formatted IDs in `UpdateUserSource`, `GetUserSourceByID`, and `DeleteUserSource`.
- Handle duplicate key errors and record not found errors with appropriate custom error messages.
Implement connection to PostgreSQL database using GORM. Embed SQL migrations and handle migration execution with logging capabilities. Define configuration structure for database settings.