To do so, we also refactor RelayTransaction to take a txid
instead of passing a tx
---
https://github.com/bitcoin/bitcoin/pull/16452/commits/9bc8b28c1d26c28edf4bbc890be97c0ad7a73cb9
Depends on D6262
Backport of Core [[https://github.com/bitcoin/bitcoin/pull/16452 | PR16452]]