Get emails of people who attended event

[geooot]

The usage would be like:

/attended --eventId <eventID>

Which would give a CSV with:

<timestamp>,<authId>,<email>

It should also support deep attended tracking (based on parentEventId). Like a query that returns the users that went to a specific eventId or the events with the parentEventId of eventId (try to avoid duplicates).

/attended --eventId <eventID> --deep

This is useful because the main big event could be like "TAMU Datathon 2020 Bootcamp" and the workshops be like different events that have the Bootcamp event as its parentEventId. So to see who "did something at TAMU Datathon 2020 Bootcamp" this query would be able to help.

Consider putting the bulk of this logic in gatekeeper (which returns a JSON api response), you could make an issue there for that.