Disable pagination with limit=0

[jspricke]

No description provided.

[Nihlus]

Core idea looks okay to me with one caveat - passing limit=0 would be an explicit choice from the client, not the server, and could be used for denial-of-service attacks against large rebuilders.

Pagination is not just a way of transferring large data sets more efficiently, but also a guard against unconstrained dumps eating up serverside resources. It'd likely be possible to bring a rebuilder to a halt by just firing off a bunch of limit=0 queries, hang up the request, and then let the server churn through massive DB materializations until it gets back to actix and sees the aborted request.

I could see this being doable with either a configuration option that allows for it (letting the rebuilder admin take responsibility for possible DoS attacks) or only allowing limit=0 for authenticated clients.