Added exception handling for unexpected errors in signal handler, request sending, and thumbnail fetching.

Refactor signal handling for graceful shutdown and improve logging.

Change import method for ElegooDisplayMapper to avoid circular import issues.

Commented out the import of ElegooDisplayCommunicator to avoid circular import issues.

Comment out dynamic imports to avoid circular import issues.

Log exceptions during connection handling for better debugging.

Refactor tests for DisplayCommunicator to use fixtures and improve structure.

Refactor _extract_fixed_length_packet method for clarity and efficiency.

Update test for data_received_number to handle EOL bytes.

Refactor signal handler to check if event loop exists before stopping it.

Updated checks for position_max in stepper_y and stepper_z.

Refactor write method to use _execute_command for command execution and improve blocking logic.