Populate country picker on make-booking-screen with all countries

[maillouxc]

This is really easy.

Use Java's Locale class to get a list of ISO countries, and then put them in an observable list in the controller for the screen, and in the initialize method of that controller, just set the list's item source to the observable list.

I'm sure there are plenty of examples on google, this is a really common task. I know for a fact it's super easy to do.