Add verbose debug logs to a variety of checks

These are high priority checks we really want to look at. I want to add
more of these debug statements to all checks in Bouncer and other parts
of GetDataHandlers, but I think this is good enough for now.

TShockAPI/GetDataHandlers.cs

@@ -2101,6 +2101,7 @@ namespace TShockAPI
 		{
 			if (args.Player == null || args.TPlayer == null || args.Data == null)
 			{
+				TShock.Log.ConsoleDebug("GetDataHandlers / OnPlayerUpdate rejected from null player.");
 				return true;
 			}