issue59: making exit more robust

[Roobxyz]

Overview

Explicitly calling sys.exit when ctrl-C is pressed.
Finally block ensures termination of reading /dev/tty.
Better signal handling on interupt.

Changes

• src/toolong/cli.py

Signal Handling Enhancements:

• Improved the request_exit function to handle termination signals more gracefully by using sys.exit(0)

• Added a try-except-finally block to handle KeyboardInterrupt and ensure the process is properly terminated by calling process.terminate() and process.wait().

Minor Adjustments:

• moved import sys inside the run, this might be unnecessary but I was getting "sys" referenced before assignment if I left it at global...