Show empty JSON icon when `value` is `null` (#5944)
* show empty json icon when value is null
* add changeset
* move empty check logic to parent component
* add changeset
* revert changes
* add changeset
* tweak
* add changeset
---------
Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
