Data prop is ignored despite being included in the types

[benwiles1]

Are you submitting a bug report or a feature request?

Feature request, but the types suggest that it might be a bug

What is the current behavior?

data prop is ignored in useFieldArray and FieldArray

What is the expected behavior?

data prop to be included when registering the field

Sandbox Link

https://codesandbox.io/s/kind-cartwright-g2kjl?file=/src/App.js

What's your environment?

final-form@4.20.1
final-form-arrays@3.0.2
react-final-form@6.5.1
react-final-form-arrays@3.1.1