Port to Gtk4

[alainm23]

Objective:

Port Taxi to Gtk4 to take advantage of the improvements and new features this version offers.

Advantages of Porting to Gtk4:

• Performance Improvements: Gtk4 provides enhanced performance compared to previous versions, resulting in a smoother and more responsive interface.

• New Functionalities: Gtk4 introduces new widgets and improvements to existing ones, allowing for a more modern and attractive user interface. For instance, the ability to use shadow effects and advanced animations.

• Wayland Compatibility: Transitioning to Gtk4 will facilitate native support for Wayland, improving compatibility with more modern desktop environments.

• Future Development: Updating to Gtk4 ensures the project's continuity and support, allowing Taxi to evolve alongside the latest Linux desktop technologies.

Next Steps:

• Assess the compatibility of the existing code with Gtk4.
• Rewrite or adapt the user interface components to utilize the new Gtk4 APIs.
• Test and fix issues during the migration.
• Document the changes made and update dependencies.