feat(chat): add in-game chat widget

This is a pretty cute widget! However, there is not yet any backend support for
chat, so that's next on the list... I think it should be pretty easy to do.
feat(chat): add backend in-game chat implementation

The server-side is not quite looking like the client-side, this needs to be
cleaned up a tad.
fix(chat): make chat autoscroll nicely

This is nice. The widget is still missing something, like an alert icon or
something. Maybe a way to pin the element instead of requiring it to be hovered.

And of course, a way to show a player's profile.