Create GameStateRepository

Use GameState.apply() to build Projection
Create GameEventHandler
Add PlayerWinEvent

src/main/kotlin/eventDemo/app/notification/PlayerWinNotification.kt

@@ -0,0 +1,13 @@
+package eventDemo.app.notification
+
+import eventDemo.app.entity.Player
+import eventDemo.shared.UUIDSerializer
+import kotlinx.serialization.Serializable
+import java.util.UUID
+
+@Serializable
+data class PlayerWinNotification(
+    @Serializable(with = UUIDSerializer::class)
+    override val id: UUID = UUID.randomUUID(),
+    val player: Player,
+) : Notification