Require setting the activation policy on the event loop (#1922)

* Require setting the activation policy on the event loop

* Run cargo fmt

* Update changelog

* Fixes and tweaks from review

* Correct comment in app_state.rs

Co-authored-by: Mads Marquart <mads@marquart.dk>

src/platform_impl/macos/mod.rs

@@ -17,6 +17,7 @@ mod window_delegate;
 use std::{fmt, ops::Deref, sync::Arc};
 
 pub use self::{
+    app_delegate::{get_aux_state_mut, AuxDelegateState},
     event_loop::{EventLoop, EventLoopWindowTarget, Proxy as EventLoopProxy},
     monitor::{MonitorHandle, VideoMode},
     window::{Id as WindowId, PlatformSpecificWindowBuilderAttributes, UnownedWindow},