implement NIVC verification

[porcuquine]

See linked comment for more context. The right answer is probably not to just implement verification in Lurk as though arecibo's SuperNova is set in stone, as this will lead to interfaces that diverge from our Nova/IVC more than necessary. It's most likely that the SuperNova data structures and workflow should actually change, and that the need for them to do so in order to cleanly implement verification usable from Lurk (as in the commented example code) will help drive understanding of the shape they should have.

Yes, it would. It's not entirely obvious what the right interface for this will be. Whereas a Nova RecursiveSnark contains the z_i needed to verify itself, a SuperNova RecursiveSnark does not. It needs to also be provided with a RunningClaim. In order to provide an interface as much like Nova's as possible, it may be necessary to refactor SuperNova in arecibo. @mpenciak is looking into this. I'll create an issue to track this understanding, and if we end up deciding to hack around it in Lurk, we can. For now, I assume the right thing is to reshape the upstream interfaces.

Originally posted by @porcuquine in #677 (comment)

[huitseeker]

@mpenciak this should now be closed, right?