Introduce RPC for Block state witness generation

[seunlanlege]

Describe the feature

This would be a custom RPC endpoint specific to reth alone, that allows users to generate the state witness of a block. This state witness can then be used in things like stateless clients, fraud provers for Optimistic L2s or trustless bridges.

Additional context

No response

[onbjerg]

Can you expand on this more? Preferably if there are existing discussions on this (e.g. in reference to later network upgrades) please include those as well. The term "state witness" in particular seems to be a bit overloaded as far as I know, so it is not entirely clear what you mean - or what the format should be etc.

[fnerdman]

turbo-geth has a block witness implementation:
Witness Builder
Formal Spec
Format

[github-actions]

This issue is stale because it has been open for 14 days with no activity.

[github-actions]

This issue was closed because it has been inactive for 7 days since being marked as stale.

[flyq]

ethereum/go-ethereum#30069