Add support for group chat member list

[AeroPurple]

What it says on the tin. I think it would be better if you could see all of the people in the group chat at a glance, see who's online and who you can talk to and whatnot. Right now the only way to do this is to scroll the list of DMs and cross-reference all of the people that are in the chat.

[iProgramMC]

I think it would be better too. This is not a bug, but a missing feature