Release cfc80d9

Refactor tile setting logic in map.gd to ensure proper tile clearing

- Implemented erase_cell before setting new tiles in set_tile and sync_tile functions to prevent overlapping tiles.
- Updated clear_map function to use erase_cell for clearing tiles instead of setting them to -1, enhancing clarity and functionality.
- Improved comments for better understanding of tile setting processes and the importance of clearing existing tiles.