```
It should be possible to grant nodes in a local network (e.g. home,
university, enterprise, ...) permission to download blocks even after
the maxuploadtarget is hit.
Currently this is only possible by setting the noban permission, which
has some adverse effects, especially if the peers can't be fully
trusted.
Fix this by extracting a download permission from noban.
```
Backport of core#19191.
Depends on D9324 and D9325.