Enhance Filterable: Facade, Conditional Logic, Custom Engines, and Provider Refactor

[kettasoft]

This PR merges the latest updates from the master branch into 2.4.2, introducing several significant enhancements and new features for the Filterable package:

Key Changes

• Filterable Facade: Added a Laravel facade for static and expressive access to filtering logic.
• Conditional Logic: Introduced the unless() method (complementing when()) for more expressive conditional configuration.
• Custom Engines: Support for user-defined filtering engines.
• Comprehensive documentation added.
• Service Provider Refactor: The provider was rewritten for greater extensibility, clearer asset publishing, improved config merging, and multiple extension hooks.
• Documentation: Expanded API docs, new guides on custom engines, conditional logic, and advanced service provider usage.
• Testing: Added test suites for facade, tap feature, provider, custom engines, and new conditional logic.
• Minor Updates: Composer/config changes for new facade registration and improved navigation in documentation.
• Deprecations: Replaced legacy documentation on when with new content covering both when and unless.

Why?

These changes make Filterable more flexible, extensible, and easier to use in advanced Laravel scenarios. Developers can now customize filtering logic, integrate via a facade, and extend the package with less friction.