Dispatch keystrokes and fix rerendering when window invalidated

Co-Authored-By: Antonio Scandurra <me@as-cii.com>

gpui/src/platform/mod.rs

@@ -41,7 +41,7 @@ pub trait Dispatcher: Send + Sync {
 }
 
 pub trait Window: WindowContext {
-    fn on_event(&mut self, callback: Box<dyn FnMut(Event, &mut dyn WindowContext)>);
+    fn on_event(&mut self, callback: Box<dyn FnMut(Event)>);
     fn on_resize(&mut self, callback: Box<dyn FnMut(&mut dyn WindowContext)>);
 }