Adding EmojiHandler to handle an exploit. Adding sendemoji permission and checks.

I know, this is not something important, but I'm going through the new packets one by one and adding events developers can work with, patching exploits, and thought this could be a core permission.

CHANGELOG.md

@@ -4,6 +4,7 @@ This is the rolling changelog for TShock for Terraria. Use past tense when addin
 
 ## Upcoming Changes
 * Add Emoji event to GetDataHandler. This packet is received when a player tries to display an emote.
+	* Adding EmojiHandler to handle an exploit. Adding `tshock.sendemoji` permission and checks. Added this permission to guest group by default.
 
 ## TShock 4.4.0 (Pre-release 10)
 * Fix all rope coils. (@Olink)

TShockAPI/DB/GroupManager.cs

@@ -65,7 +65,8 @@ namespace TShockAPI.DB
 						Permissions.canpartychat,
 						Permissions.cantalkinthird,
 						Permissions.canchat,
-						Permissions.synclocalarea));
+						Permissions.synclocalarea,
+						Permissions.sendemoji));
 
 				AddDefaultGroup("default", "guest",
 					string.Join(",",

TShockAPI/Handlers/EmojiHandler.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace TShockAPI.Handlers
+{
+	/// <summary>
+	/// Handles an exploit and checks for permissions.
+	/// </summary>
+	public class EmojiHandler
+	{
+		public void OnEmoji(object sender, GetDataHandlers.EmojiEventArgs args)
+		{
+			if (args.PlayerIndex != args.Player.Index)
+			{
+				TShock.Log.ConsoleError($"EmojiHandler: Packet is spoofing to be player ID {args.PlayerIndex}! - From [{args.Player.Index}]{args.Player.Name}");
+				args.Handled = true;
+				return;
+			}
+
+			if (!args.Player.HasPermission(Permissions.sendemoji))
+			{
+				args.Player.SendErrorMessage("You have no permission to send emotes!");
+				args.Handled = true;
+				return;
+			}
+		}
+	}
+}

TShockAPI/Permissions.cs

@@ -468,6 +468,9 @@ namespace TShockAPI
 
 		[Description("Player can resync themselves with server state.")]
 		public static readonly string synclocalarea = "tshock.synclocalarea";
+
+		[Description("Player can send emotes.")]
+		public static readonly string sendemoji = "tshock.sendemoji";
 		#endregion
 		/// <summary>
 		/// Lists all commands associated with a given permission