Initialise sockets w/ fastify-socket.io

[athifongoqa]

Listen on:

• 'connection'
  (parameters: socket)
• 'user-join-show'
  (parameters: participant)
• 'call'
  (parameters: participant, socketId)
• 'leave-show'
  (parameters: room)
• 'disconnect'
  (parameters: reason)
• 'playback-update'
  (parameters: playerState, showId)
• 'playback-initial-sync'
  (parameters: toUserId, playerState)
• 'message-send'
  (parameters: showId, message, user}, callback)
• 'toggle-mute'
  (parameters: showId, peerId, isMuted)