due to the requirement for adding doors and door bodies before initializing body lifecycle manager, move lifecycle manager to game initialization and create more bodies with this manager

- Body defines an object's size and shape
- Body provides a universal function to detect collision

- change the way modules are imported, defining module directly in globals
- move enemy data and heart data into individual files and /data directory

- door connects two rooms
- detects if player enters a door, if so, then switch room and update player location