ring: reduce allocs and ~5–10% faster Sign/Verify (precomputed H_p, pooled scratch, EncodeInto)#1

jorgecuesta wants to merge 2 commits intopokt-network:masterpokt-network/ring-go:masterfrom

jorgecuesta:perf/ringsig-verify-allocs-and-challenge-fastpathjorgecuesta/ring-go:perf/ringsig-verify-allocs-and-challenge-fastpathCopy head branch name to clipboard