Add foldable view for hierarchical (json) structures

[htlemke]

It is useful for status reporting and potential recovery of states to upload hierarchical device configurations (typically in json format).
Viewing/browsing such potentially large structured data would ideally require a folded/extendable view, e.g. a json viewer built into scilog.
It would be great if such could be implemented (e.g. https://github.com/pgrabovets/json-view ; likely other products available), as the typical alternative is downloading the json file and exploring its content using a txt file viewer.