React Aria's Collection component injects an `id` prop into rendered
children. When children were wrapped in Fragment, this caused
"Invalid prop `id` supplied to `React.Fragment`" errors on render.
BREAKING CHANGE: The `cell` and `header` properties in `ColumnConfig`
now return `ReactElement` instead of `ReactNode`. Cell and header
functions that return non-element values must be updated to always
return a valid element.
Signed-off-by: Johan Persson <johanopersson@gmail.com>
Johan Persson
caeb9ada1d