Optimise back-endorsement chain handling #7736
Description
We may want to optimise back-endorsement chain prefetch.
In #7711 we went the simpler way and only swapped receipt format, and didn't include the chain in the snapshot.
We may still do it though, here's the up/down sides of snapshot-backed-in-chain, either separately or bake it into the snapshot too.
Cons
- Snapshot size may grow?
- Although we can make it optional of too big, or only fill it up to the certain size and fetch the rest
Pros
- Piggy-pack on snapshot auto-download