feature: close preference window with Esc

[WhyNotHugo]

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Is your feature request related to a problem? Please describe.

When the preferences window is open, it can only be closed via the desktop-specific keyboard shortcut to close a window.

Describe the solution you'd like

Being able to quickly dismiss it with Esc would be quick and handy. It's a shortcut that I intuitively expected to work.

Describe alternatives you've considered

I guess an "okay" button could be used? It might be ambiguous given that preferences seem to be saved automatically and don't need a separate action to confirm.

Additional context

n/a