[feature request] leave insert mode onFocusChange event

It would be very useful to have a way to leave insert mode on onFocusChange (specifically onWindowChange).
When I code a web application I often quickly switch from window to window using alt+shift or similar shortcut to check the result and go back to visual studio code for fine tuning the page. Sometimes (a lot of time) I forget that I didn't press escape to leave insert mode before switching the window so I start to press j or any other navigation key but because I am still in insertion mode I have jjjjjjjjjj that is written.. and because I can't escape the mode and press u to undo because the last modification will also get lost, I have to manually remove the unwanted jjjjjjj character on the line which is double time a pain in the... hands.

Please if you could implement this option as soon as you can, I am sure many people will also like that.
Or maybe just telling me if you think of a quick adjustment in VSC to allow this effect.

Thanks

Start by reviewing how the VS Code extension observes onFocusChange, specifically onWindowChange, and how it tracks insert mode. Determine the expected behavior and configuration surface from the issue, then verify that switching windows can leave insert mode without losing the preceding edit.