[widgets][dataformateditor] Refactor to allow folding of content

The editor can get pretty long pretty quickly if many
fields are added. Especially array entries or object
entries. Making their repsective editors foldable
allows the user to more easily go through the content
of the editor.
6 jobs for 236_add_folding_to_dataformat_editors in 56 minutes (queued for 4 seconds)