Make new_window asynchronous (#4297)

* Make new_window asynchronous

* fix clippy

packages/desktop/src/lib.rs

@@ -48,7 +48,9 @@ pub mod trayicon;
 // Public exports
 pub use assets::AssetRequest;
 pub use config::{Config, WindowCloseBehaviour};
-pub use desktop_context::{window, DesktopContext, DesktopService, WeakDesktopContext};
+pub use desktop_context::{
+    window, DesktopContext, DesktopService, PendingDesktopContext, WeakDesktopContext,
+};
 pub use event_handlers::WryEventHandler;
 pub use hooks::*;
 pub use shortcut::{HotKeyState, ShortcutHandle, ShortcutRegistryError};