feat: add Window::is_resizable (#2171)

* feat: add `Window::is_resizable`

* move it right after `set_resizable`

src/platform_impl/linux/wayland/window/mod.rs

@@ -336,6 +336,11 @@ impl Window {
         self.send_request(WindowRequest::Resizeable(resizable));
     }
 
+    #[inline]
+    pub fn is_resizable(&self) -> bool {
+        true
+    }
+
     #[inline]
     pub fn scale_factor(&self) -> u32 {
         // The scale factor from `get_surface_scale_factor` is always greater than zero, so