Add UUID for user in order to allow for more than 1 IP for a single user

[jakerella]

When a user is playing on a mobile browser or laptop and they switch networks (like from wifi to mobile data, or from one wifi source to another) then the system is registering them as two different users since the system uses IP address for stats tracking. We could switch this to use a UUID generated on the back end and then stored in the browser's localstorage, then sent from front end to back end with each request. That way we can track a single user across networks.