Projection was now built on listener events

Create ProjectionBus and use it with listeners
add EventStream::getByVersion

src/main/kotlin/eventDemo/libs/event/EventStreamInMemory.kt

@@ -41,4 +41,7 @@ class EventStreamInMemory<E : Event<*>> : EventStream<E> {
     events
       .filter { version.contains(it.version) }
       .toSet()
+
+  override fun getByVersion(version: Int): E? =
+    events.find { version == it.version }
 }