Packet filtering for those who never finish the handshake

This also kicks those who never finish handshaking upon chat now. (To free up the resources a bit I guess?)

Before a player finishes the connection handshake, the server will check if it's necessary to send them a packet - it checks against a list of necessary packets like:

- ContinueConnecting (Send User Slot),
- PlayerSpawnSelf (CompleteConnectionAndSpawn),
- WorldInfo (Which the server does a further check if the player is at the appropriate state to be sent the world info)
- Status
- Disconnection
- TileFrameSection & TileSendSection

TShockAPI/TShock.cs

@@ -1494,6 +1494,7 @@ namespace TShockAPI
 
 			if (!tsplr.FinishedHandshake)
 			{
+				tsplr.Kick(GetString("Your client didn't finish the handshake."), true);
 				args.Handled = true;
 				return;
 			}