fix(st): use the Lunar world ID for new worlds (#5168)
Stationeers renamed the Moon world to Lunar. With the old default a fresh
install logged "No matching world found with id 'moon'", created no world
and never opened the game port. worldtype is now Lunar. The world ID is
only used when the save does not exist yet, so existing moon_save worlds
keep loading.
Fixes #5167