feat(perf): speed up construction of bbjs Frs & cache zero hashes in ephemeral trees (redo)#11894

ludamad merged 4 commits intomasterAztecProtocol/aztec-packages:masterfrom

revert-11893-revert-11851-db/ts-fr-hash-optsAztecProtocol/aztec-packages:revert-11893-revert-11851-db/ts-fr-hash-optsCopy head branch name to clipboard