Refactors backend modules to enhance maintainability and implements a database backup feature.
Updates core framework and other components to the latest versions, addressing identified issues and improving system stability.

- Moves media files from `public/uploads/media` to `public/media`.
- Refactors backend controllers to use DataTables for improved data handling.
- Adds database backup module for easier data management.
- Updates elFinder library for better file management.
- Updates ext_module_generator library.
- Removes unused paginator library.
- Adds Locked functionality to manage locked users.