chore: adding overriding scenes and prefabs example#3161

NoelStephensUnity merged 10 commits intodevelop-2.0.0Unity-Technologies/com.unity.netcode.gameobjects:develop-2.0.0from

example/server-client-unique-scenes-and-prefabsUnity-Technologies/com.unity.netcode.gameobjects:example/server-client-unique-scenes-and-prefabsCopy head branch name to clipboard