Can't pass a className to RadioGroup

[GrossDesignCo]

Describe the bug

generic components Radio & RadioGroup are missing handling for className in userProps.

Likely low-priority since most folks use custom components but nice to have :)

Working example in Input

Compare to RadioGroup

To Reproduce

Repro: https://codesandbox.io/p/sandbox/keen-sound-h6zk5d

[joepuzzo]

Hmm where would you expect the class to end up ?

[GrossDesignCo]

In the default/native inputs case I'd expect the className to get applied to the fieldset for RadioGroup. For Radio it's a bit more debatable, but I think the most useful would be on the label since that wraps the input.

As a rule of thumb on TDS we'd try to put the className on the outermost element within the component's markup, and if necessary add another prop like inputProps (maybe inputElementProps or something in this case) so that it was easy to target for folks.