allow marking notifications as read in ctrl+k

ctrl + k has become the main way i navigate around the platform but one thing that bugs me is when it shows that you have a ping in a channel and you actually have to go to the channel and read the messages to get rid of the notif, instead of just being able to mark it as read in the ctrl+k menu. i think it'd be a lot easier if we were actually able to do this and also allowing people to mute channels through this would help too.