Muting

[kjhobin]

Duplicate of Issue #7

• As a user, I want to be able to mute my microphone so that others can't hear me but I am still in the space.
• As a user, I want to mute my camera so that others can't see me but I am still in the space.
• As a user, I need to be able to tell when I have muted my microphone and/or my camera.
• As a user, I want to be able to tell when a nearby user has muted their microphone.