Add Window::is_minimized

Co-authored-by: Kirill Chibisov <contact@kchibisov.com>
Co-authored-by: Markus Siglreithmaier <m.siglreith@gmail.com>

src/platform_impl/macos/window.rs

@@ -864,6 +864,11 @@ impl WinitWindow {
         }
     }
 
+    #[inline]
+    pub fn is_minimized(&self) -> Option<bool> {
+        Some(self.isMiniaturized())
+    }
+
     #[inline]
     pub fn set_maximized(&self, maximized: bool) {
         let is_zoomed = self.is_zoomed();