This module captures orphan tracking code for tx relay.
Can be reviewed with --color-moved=dimmed-zebra
This is a backport of [[https://github.com/bitcoin/bitcoin/pull/21148 | core#21148]] [1/14]
https://github.com/bitcoin/bitcoin/pull/21148/commits/9d5313df7eedad8562c822f5477747e924929fd3
Note: I had to change a couple of `uint256` type to `TxId` in a test.