eframe error handling (#2433)

* eframe::run_native: return errors instead of crashing

* Detect and handle glutin errors

* egui_demo_app: silence wgpu log spam

* Add trace logs for why eframe is shutting down

* Fix: only save App state once on Mac

* Handle Winit failure

* Log where we load app state from

* Don't panic on zero-sized window

* Clamp loaded window size to not be too tiny to see

* Simplify code: more shared code in window_builder

* Improve code readability

* Fix wasm32 build

* fix android

* Update changelog

crates/eframe/src/epi.rs

@@ -708,6 +708,7 @@ impl Frame {
     #[doc(alias = "exit")]
     #[doc(alias = "quit")]
     pub fn close(&mut self) {
+        tracing::debug!("eframe::Frame::close called");
         self.output.close = true;
     }