perf(epoch): replace AutoHashMap with array lookup in reward/penalty caches#286

lodekeeper-z wants to merge 4 commits into

ChainSafe:mainChainSafe/lodestar-z:mainfrom

lodekeeper-z:perf/array-lookup-epoch-cachelodekeeper-z/lodestar-z:perf/array-lookup-epoch-cacheCopy head branch name to clipboard