Do not hide Flag button in user menu, rather display a warning when no flags can be reviewed

It was recently changed to hide reviewables in the new user menu when handled.

I like this change and didn’t like handled flags appearing in the menu.

However, when there’s nothing to review the button is gone. Instead of hiding the button, there can instead be a warning.

It could look something like this:
The down arrow could bring you to /review or be removed.
It’s a bit rough but it could work.