remove modules and have single event manager (atomics feature parity + preparation for local state)

src/default/event.rs

@@ -1,9 +1,9 @@
-use iris_core::DefaultEvent;
+use iris_core::Event;
 
 #[derive(Eq, PartialEq, Hash, Clone)]
 pub struct Submit;
-impl DefaultEvent for Submit {}
+impl Event for Submit {}
 
 #[derive(Eq, PartialEq, Hash, Clone)]
 pub struct Edited;
-impl DefaultEvent for Edited {}
+impl Event for Edited {}