App now refreshes clips before refreshing the window list

This avoids the app sometimes thinking it's unclipped for a second if another app changes the clipping bounds.
Also changed looping functions to have an explicit loop function that calls the inner function, for clarity and so the inner function can be called separately without spawning another loop.

First working version

Seems to be working fine - need a better way to decouple ui.py from main logic in main.py - callback layout feels messy
Also want to add a checkbox in future to automatically clip to any fullscreen application
As usual, use at your own risk - I made this for personal use for games that haven't been set up properly to prevent cursor drift on multi-monitor setups or when running in a window