Refactor Disk, MediaExporter, HLSExporter, and MediaOpener for PHP 7.…

[JaydeepRokade]

This PR refactors and improves the internal code quality of the following classes in the ProtoneMedia\LaravelFFMpeg package:

Disk.php

MediaExporter.php

HLSExporter.php

MediaOpener.php

✅ Improvements Made ✅ Replaced PHP-reserved method clone() with cloneDisk() and cloneOpener() to ensure future compatibility.

✅ Added modern PHP 7.4+ typed properties for better type safety.

✅ Improved readability, indentation, and method docblocks for maintainability.

✅ Ensured consistency across the exporter and filesystem-related classes.

✅ Refactored inline callbacks to use concise fn() syntax where applicable.

✅ No changes to public-facing functionality (backward compatible).

📌 Why This Change? To modernize the codebase with current PHP practices.

To remove ambiguity around reserved method names (clone()).

To support future upgrades of the PHP version in Laravel projects.

To make the codebase easier for new contributors and maintainers to understand and work with.

Please feel free to suggest changes. Happy to iterate if needed! 🙌