refactor: restructure game logic and state management into separate modules

- Moved game logic from `game.rs` to `game/mod.rs` and `game/state.rs` for better organization.
- Updated `App` to utilize the new `Game` struct and its state management.
- Refactored error handling
- Removed unused audio subsystem references

tests/parser.rs

@@ -1,5 +1,6 @@
 use pacman::constants::{BOARD_CELL_SIZE, RAW_BOARD};
-use pacman::map::parser::{MapTileParser, ParseError};
+use pacman::error::ParseError;
+use pacman::map::parser::MapTileParser;
 
 #[test]
 fn test_parse_character() {