Replace simple_event_shunt macro with proc macro

This macro is pretty complicated and I needed to add the ability to
clean keywords, so it makes more sense to have this be a proc macro.

src/server/dispatch.rs

@@ -1,5 +1,6 @@
 use super::*;
 use log::{debug, error, trace, warn};
+use macros::simple_event_shunt;
 use std::sync::{Arc, OnceLock};
 use wayland_client::globals::Global;
 use wayland_protocols::{