Show a user-friendly error message if undo is triggered via an action with nothing to undo

[abdnh]

Originally reported on https://forums.ankiweb.net/t/bug-report-for-ios-error-dialog-undoempty-when-shaking-device-on-first-card/70006

The actions-nothing-to-undo translation string can be reused.

[AB-boi]

It would be very useful to know when I hit undo by mistake cause I worry if something was undone or not.

[AB-boi]

Does Anki Desktop have such a notification that says nothing to undo?

[abdnh]

It looks like desktop used to say "Nothing to undo" in older versions.

[AB-boi]

Could you please consider bringing that back for desktop? It’s quite useful.