feat: add notification domain events, listener, and module

myteamwallet_backend/src/notifications/events/player-created.event.ts

@@ -0,0 +1,8 @@
+export class PlayerCreatedEvent {
+  constructor(
+    public readonly teamId: number,
+    public readonly actorUserId: number,
+    public readonly playerId: number,
+    public readonly playerName: string,
+  ) {}
+}