Allow not preventing default event behaviors on wasm (#7304)

# Objective

On wasm, bevy applications currently prevent any of the normal browser hotkeys from working normally (Ctrl+R, F12, F5, Ctrl+F5, tab, etc.).

Some of those events you may want to override, perhaps you can hold the tab key for showing in-game stats?

However, if you want to make a well-behaved game, you probably don't want to needlessly prevent that behavior unless you have a good reason.

Secondary motivation: Also, consider the workaround presented here to get audio working: https://developer.chrome.com/blog/web-audio-autoplay/#moving-forward ; It won't work (for keydown events) if we stop event propagation.

## Solution

- Winit has a field that allows it to not stop event propagation, expose it on the window settings to allow the user to choose the desired behavior. Default to `true` for backwards compatibility.

---

## Changelog

- Added `Window::prevent_default_event_handling` . This allows bevy apps to not override default browser behavior on hotkeys like F5, F12, Ctrl+R etc.

Author: johanhelsing

src/winit_windows.rs

@@ -110,6 +110,9 @@ impl WinitWindows {
                     panic!("Cannot find element: {}.", selector);
                 }
             }
+
+            winit_window_builder =
+                winit_window_builder.with_prevent_default(window.prevent_default_event_handling)
         }
 
         let winit_window = winit_window_builder.build(event_loop).unwrap();