Export hierarchy / drive / children

[joepio]

AtomicServer has a CLI option for exporting all data from a server, and it's obviously possible to export a query / selection of data, but how does a user export a whole drive? Or all children from some specific point?

• @turkhale wants some button to export all resources in a drive as JSON
• ideally, it is a download from some endpoint, because that scales way further than some front-end GUI copy/paste textual implementation.

[Polleps]

We could add a json format option to the new export endpoint in #931