FS: Showing Participants in Waiting Room

[skassam21]

• When a new user arrives at the waiting room, you can see the users first and last name appear (use sockets so all users will see anyone that appears)
• A maximum of two participants at a time, so if a third user comes, we show an error message (a dialog that you can't join this link)
• Only the creator of the interview can start the interview