macOS: iconify property doesn't change after minimize when resizable is false

The iconized property behaves weirdly when resizable is false.
The property doesn't change when the os minimize button is called.
The property also resets to false (without deminimizing) when iconized is set to true when resizable is false. (workaround is to temporarily change resizable to true).

```
public class JavaFXBugIconified extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {

        VBox pin = new VBox();
        Button button = new Button("iconified");

        pin.setPrefWidth( 600);
        pin.getChildren().add(button);
        pin.getChildren().add(new ToggleButton());

        primaryStage.setResizable(false);
        primaryStage.setScene(new Scene(pin));

        primaryStage.show();


        // Not important for the bug, but useful for testing
        button.onActionProperty().set((e) -> {
            primaryStage.setResizable(true);
            primaryStage.setIconified(true);
            new Thread(() -> {
                try {
                    System.out.println("ASDF");
                    Thread.sleep(2000);
                    Platform.runLater(() -> {
                        primaryStage.setIconified(false);
                        primaryStage.setResizable(false);
                    });
                } catch (Throwable ee) {
                    ee.printStackTrace();
                }
            }).start();
        });
    }
}
```