Wip - Export communities endpoint

[zachfeldman]

Total Work In Progress, but I got stuck for now, so thought I'd post what I have so far!

I can make a CURL request to the /community/export endpoint but I get Query deserialize error: unknown variant TopMonth, expected NeworOld`.

I'm copying heavily from the list endpoint.

I'm thinking this endpoint will need less information than that endpoint, and will return a CSV or some other format. A bit of work to get to there, but this is a start.

One day this could also be offloaded to a delayed job of some kind but I figure initially there aren't that many communities folks can be subscribed to anyway.

[phiresky]

using csv seems like a bad idea, any reason to not use json? or jsonl

[Nutomic]

Feel free to reopen this after addressing the comments.