Add channel group to TsFullClient

[scheissegalo]

Is your feature request related to a problem? Please describe. Yes, no channel group support.

Describe the solution you'd like Add this:

        public CmdR ChannelGroupAddClient(ChannelGroupId groupId, ChannelId channelId, ClientDbId clientDbId)
            => SendVoid(new TsCommand("setclientchannelgroup") {
            { "cgid", groupId },
            { "cid", channelId },
            { "cldbid", clientDbId },
                });

to TsFullClient.cs