Add optimization capabilities to connect

[johnrom]

Currently connect passes Formik's full state to class components, but it could be more redux-like, selecting bits of state and being very optimized:

const RotateWhenSubmitting_Raw = (props: { isSubmitting: boolean }) => (
  <span className={`rotate-when-submitting ${props.isSubmitting ? "submitting" : ""}}>
    <SpinnerSvg />
  </span>
);
const RotateWhenSubmitting = connect(state => { isSubmitting: state.isSubmitting })(RotateWhenSubmitting_Raw);

This would be simple to do on top of #3089

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[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 60 days

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 60 days