refactor event handling to consume base class for lifecycling

src/infrastructure/Events/IEventSource.ts

@@ -0,0 +1,11 @@
+export interface IEventSource<T> {
+    on(handler: EventHandler<T>): IEventSubscription;
+}
+
+export interface IEventSubscription {
+    unsubscribe(): void;
+}
+
+export type EventHandler<T> = (data: T) => void;
+
+