Only show the "program not responding" dialog on interaction with an unresponsive window.

### Problem

This is based on a suggestion by the user _rwrv!_ on the Discord channel. It's about the dialog that shows when an app is not responding, containing the buttons _Wait_ and _Force Quit_.

> I think there shouldn't be an interaction popup immediately on something not responding, it should instead be triggered by attempting to interact with the not responding window, with a visual indicator like desaturation
>
> many games hold a single frame while loading like this, which isn't an issue on Windows where it just makes the window grey for a little bit

Often, these dialogs can be annoying and unnecessary. An app could just freeze for a moment, and all you have to do is wait; similarly, a game could take a while to launch; or maybe a third-party application is just buggy.

### Proposal

When a program goes unresponsive, don't show the dialog right away; simply grey-out the window (a visual indicator) until the user tries to interact with it. When the window is clicked, the dialog to _wait_ or _kill_ the app pops up.

### Prior Art (Optional)

_No response_