The player.go and ui.go files have been separated into their own
separate packages.
Additionally, all go.mod files have been modified to point to local
directories.
This change should not only clean up the frontend codebase, but also
make it easier to send/recieve data from the backend (at least
regarding the player)
Player has health, level, exp (which is gained constantly while online)
and ambition (which affects the rate of exp gain). More stats will be
added later. This is mostly just a test implementation. Will clean up
later.
