[React 19] allow opting out of automatic form reset when Form Actions are used

## Summary repo: https://github.com/stefanprobst/issue-react-19-form-reset react 19@beta currently will automatically reset a form with uncontrolled components after submission. it would be really cool if there was a way to opt out of this behavior, without having to fall back to using controlled components - especially since component libraries (e.g. [`react-aria`](https://react-spectrum.adobe.com/react-aria/forms.html)) have invested quite a bit of time to work well as uncontrolled form elements. the main usecase i am thinking of are forms which allow saving progress, or saving a draft, before final submit. currently, every "save progress" would reset the form.