On Windows and macOS, add API to enable/disable window controls (#2537)

* On Windows and macOS, add API to enable/disable window controls

* fix build

* missing import

* use `WindowButtons` flags

* rename to `[set_]enabled_buttons`

* add example, fix windows impl for minimize

* macOS: Fix button enabling close/minimize while disabling maximized

* Update src/platform_impl/windows/window.rs

Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

* compose the flags on a sep line, use `bool::then`

Co-authored-by: Mads Marquart <mads@marquart.dk>
Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

src/platform_impl/macos/appkit/window.rs

@@ -180,6 +180,12 @@ extern_methods!(
         #[sel(isResizable)]
         pub fn isResizable(&self) -> bool;
 
+        #[sel(isMiniaturizable)]
+        pub fn isMiniaturizable(&self) -> bool;
+
+        #[sel(hasCloseBox)]
+        pub fn hasCloseBox(&self) -> bool;
+
         #[sel(isMiniaturized)]
         pub fn isMiniaturized(&self) -> bool;