refactor event handling to consume base class for lifecycling

src/infrastructure/Events/EventSubscriptionCollection.ts

@@ -0,0 +1,12 @@
+import { IEventSubscription } from './IEventSource';
+
+export class EventSubscriptionCollection {
+    private readonly subscriptions = new Array<IEventSubscription>();
+    public register(...subscriptions: IEventSubscription[]) {
+        this.subscriptions.push(...subscriptions);
+    }
+    public unsubscribeAll() {
+        this.subscriptions.forEach((listener) => listener.unsubscribe());
+        this.subscriptions.splice(0, this.subscriptions.length);
+    }
+}