Material-ui-pickers: helperText equivalent

[dandv]

Is your feature request related to a problem? Please describe.
When the date has a valid format but is invalid for other reasons, the text displayed under the TextField shows the date format in red. That doesn't help the user figure out what's wrong.

Describe the solution you'd like
A helperText attribute would enable displaying specific errors instead of the format.

Describe alternatives you've considered
renderInput={props => <TextField helperText="test" {...props} />} didn't show the helper text.

[dmtrKovalenko]

helperText was moved to renderInput

renderInput={props => <TextField {...props}  helperText={null} />}
renderInput={({ helperText, ...props }) => <TextField {...props} />}

[oliviertassinari]

@dandv The issue is with the order of the spreading, always spread the props first, as it's done in the demos: https://next.material-ui-pickers.dev/demo/datepicker#different-views.

-renderInput={props => <TextField helperText="test" {...props} />}
+renderInput={props => <TextField {...props} helperText="test" />}

This would have made a great StackOverflow question! I'm sure somebody else will fall into this trap, I have seen it a couple of time with the Autocomplete.