Allow to close windows in alt-tab windows-list view

### Problem

There is a need to close windows without opening them and without closing the whole app.

This is a privacy concern. E.g. a kid sits with you and you don't want to show whatever you have in other window. Or you're in class presenting something and you don't want to accidentally show answers to a quiz.

### Proposal

Add a closing button similar to every entry in windows list, so it is possible to close certain windows with a mouse.
Add a key combination to close chosen window (alt-q or alt-tab-q) and expose it in settings for customization.

### Prior Art (Optional)

_No response_