Implement GUILD_APPLICATION_COMMAND_COUNTS_UPDATE

Created by: Lulalaby

Usage:

        private Task Client_GuildApplicationCommandCountUpdated(DiscordClient sender, GuildApplicationCommandCountEventArgs e)
        {
            Console.WriteLine($"Application Command count updated in {e.Guild.Name}");
            Console.ForegroundColor = ConsoleColor.Gray;
            Console.WriteLine($"Slash commands: {e.SlashCommands}");
            Console.ForegroundColor = ConsoleColor.Blue;
            Console.WriteLine($"User context menu commands: {e.UserContextMenuCommands}");
            Console.ForegroundColor = ConsoleColor.Yellow;
            Console.WriteLine($"Message context menu commands: {e.MessageContextMenuCommands}");
            Console.ResetColor();
            return Task.CompletedTask;
        }