Move the DroomsGame back to impl, so it can be shared between GUI and launchers

DroomsGame moved back to impl, because it being used from swing-gui and swing-gui can't depend on drooms-game-launcher (e.g. shade errors, multiple logback.xml configs,..).

Also remove launcher-game dependency from launcher-tournament as its not needed and it also causes errors when building the jar (maybe shaded jar can't be included in another shaded jar? not sure)

The DroomsGame class could even be moved to -api as it depends only on classes from there.