```
If ASN bucketing is used, return a corresponding AS
used in bucketing for a given peer.
```
Partial backport 3/4 of core [[https://github.com/bitcoin/bitcoin/pull/16702 | PR16702:]]:
https://github.com/bitcoin/bitcoin/pull/16702/commits/e4658aa8eaf1629dd5af8cf7b9717a8e72028251
Depends on D8195.