Feature Request: Add meta data property on form object (final-form-set-form-data)

[596050]

To add an optional data object on the form. This would allow for arbitrary metadata to be set on the form like it can be set on the field with https://github.com/final-form/final-form-set-field-data#readme which is very useful except where the field is removed from the DOM and then replaced. Therefore some way of persisting arbitrary values regardless of the aforementioned within the form would be useful.

I would be more than willing to volunteer to create the feature if needed.

What is the current behavior?
As far as I am aware the only alternative to this is using external state outside of a form component.

What is the expected behavior?
To allow metadata to be set on the form instead of exclusively on fields.