Add another (test) map
make BasketballField available as regular map. maybe should make it destructable when not in mission mode *shrugs*

--HG--
rename : share/hedgewars/Data/Maps/Basketball/CMakeLists.txt => share/hedgewars/Data/Maps/BasketballField/CMakeLists.txt
rename : share/hedgewars/Data/Maps/Basketball/map.cfg => share/hedgewars/Data/Maps/BasketballField/map.cfg
rename : share/hedgewars/Data/Maps/Basketball/map.png => share/hedgewars/Data/Maps/BasketballField/map.png
rename : share/hedgewars/Data/Maps/Basketball/mask.png => share/hedgewars/Data/Maps/BasketballField/mask.png
rename : share/hedgewars/Data/Maps/Basketball/preview.png => share/hedgewars/Data/Maps/BasketballField/preview.png
rename : share/hedgewars/Data/Maps/Basketball/preview@2x.png => share/hedgewars/Data/Maps/BasketballField/preview@2x.png