Save duplication partial evaluation in evalcheck and ring_switch

[jimpo-ulvt]

Both evalcheck and ring_switch may perform the same evaluate_partial_high operation on multilinear polynomial witnesses. In evalcheck, this occurs when computing projections. The multilinears then get stored in a memoization map to make sure they are not recomputed in evalcheck. Then in ring_switch, the prover computes the partial high evaluations to compute the tensor algebra elements sent. The prover should save the computation of the projection, if available, so it is not recomputed during ring switching.