• Has this change been discussed on the forum or in an issue before?
• Does the code follow the SFML Code Style Guide?
• Have you provided some example/test code for your changes?

Description

Add events to trigger on window minimization and maximization for Windows, MacOS, and Linux platforms.
Event::Minimize triggers when the window is minimized, and Event::Maximized triggers on window maximization.

This PR is related to the issue #3294

Tasks

• Tested on Linux: This needs a bit further verification. The window manager on WSL does not comply with the typical Linux, ones, so there should be some further testing to see if the events (particularly Minimized) trigger properly.
• Tested on Windows
• Tested on macOS
• Tested on iOS
• Tested on Android

How to test this PR?

Open a window on the supported platforms, and detect whether the minimized and maximized events are triggering. This is easiest done through an example similar to the one below. The minimize event should trigger when the minimize button is clicked on the window, and the maximized event should trigger when the maximize button is clicked.

Minimal example:

#include <SFML/Graphics.hpp>

int main()
{
    sf::RenderWindow window(sf::VideoMode({1280, 720}), "Minimal, complete and verifiable example");
    window.setFramerateLimit(60);

    while (window.isOpen())
    {
        while (const std::optional event = window.pollEvent())
        {
            if (event->is<sf::Event::Closed>())
                window.close();
            if (event->is<sf::Event::Minimized>()) std::cout << "Minimized\n";
            if (event->is<sf::Event::Maximized>()) std::cout << "Maximized\n";
        }

        window.clear();
        window.display();
    }
}