wayland/toplevel: add close() request

Closes #37

src/wayland/toplevel_management/qml.cpp

@@ -32,6 +32,7 @@ void Toplevel::onClosed() {
 }
 
 void Toplevel::activate() { this->handle->activate(); }
+void Toplevel::close() { this->handle->close(); }
 
 QString Toplevel::appId() const { return this->handle->appId(); }
 QString Toplevel::title() const { return this->handle->title(); }

src/wayland/toplevel_management/qml.hpp

@@ -56,6 +56,10 @@ public:
 	/// The request may be ignored by the compositor.
 	Q_INVOKABLE void activate();
 
+	/// Request that this toplevel is closed.
+	/// The request may be ignored by the compositor or the application.
+	Q_INVOKABLE void close();
+
 	/// Request that this toplevel is fullscreened on a specific screen.
 	/// The request may be ignored by the compositor.
 	Q_INVOKABLE void fullscreenOn(QuickshellScreenInfo* screen);