InGame update messages include a timestamp which is passed to the ClientRead methods

Now only used in character position syncing, but some other entities may also have an use for it (e.g. discarding outdated data)

Subsurface/Source/Map/Submarine.cs

@@ -1079,7 +1079,7 @@ namespace Barotrauma
             msg.Write(Velocity.Y);
         }
 
-        public void ClientRead(NetIncomingMessage msg)
+        public void ClientRead(NetIncomingMessage msg, float sendingTime)
         {
             subBody.TargetPosition  = new Vector2(msg.ReadSingle(), msg.ReadSingle());
             subBody.Velocity        = new Vector2(msg.ReadSingle(), msg.ReadSingle());