missing data-readonly attribute on RadioGroup.ItemControl and RadioGroup.ItemIndicator

[jcmonnin]

The missing data-readonly attributes on the RadioGroup.ItemControl and RadioGroup.ItemIndicator make it cumbersome to apply a different style when the radio group is read only.

This probably applies to different components and attributes as well.

From discord chat:

The radiogroup doesn't set data-readonly on the children. There are a few properties in the dataset of the context that are missing > compared to checkbox. Is this deliberate?
I was trying to style a readonly radio button, and couldn't do it the same way than on the checkbox.

fabienml — Today at 9:27 AM
Unlike checkbox, a radio button doesn't live on its own, it is always in a radio group, so it's the radio group that is read only. (
You can style it with some descendant selector but it will be cumbersome. Please open an issue for me to add the needed data-*, > i'm sure there are others than data-readonly that i've not added.