Add a sound for message notification

[rozurashii]

I would love some kind of sound to alert me to receiving a message in the clan chat, especially when I'm in a mission and not paying close attention to any UI flashes. We have a ghost clan so I don't receive messages often enough to be in the habit of checking for them, but I have missed opportunities to run missions with my clan mates because I didn't see the message in time (ie running endless mission solo and my friend leaves before I finish). My preference would be something like the steam chat noise which I find obvious but not obtrusive.

[[DE]George]

Thanks for the suggestion, we will look into that.