feat: expose NetworkObject.GetNetworkBehaviourAtOrderIndex (#2724)

Author: ShadauxCat

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -10,6 +10,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Added
 
+- exposed NetworkObject.GetNetworkBehaviourAtOrderIndex as a public API (#2724)
 - Added context menu tool that provides users with the ability to quickly update the GlobalObjectIdHash value for all in-scene placed prefab instances that were created prior to adding a NetworkObject component to it. (#2707)
 - Added methods NetworkManager.SetPeerMTU and NetworkManager.GetPeerMTU to be able to set MTU sizes per-peer (#2676)
 - Added `GenerateSerializationForGenericParameterAttribute`, which can be applied to user-created Network Variable types to ensure the codegen generates serialization for the generic types they wrap. (#2694)

com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs

@@ -1355,7 +1355,7 @@ internal ushort GetNetworkBehaviourOrderIndex(NetworkBehaviour instance)
             return 0;
         }
 
-        internal NetworkBehaviour GetNetworkBehaviourAtOrderIndex(ushort index)
+        public NetworkBehaviour GetNetworkBehaviourAtOrderIndex(ushort index)
         {
             if (index >= ChildNetworkBehaviours.Count)
             {