Build better bridges

[acolytec3]

As of this writing, we should always expect a proof to accompany any block header that Ultralight receives for pre-Shapella blocks. We don't have a comprehensive history network bridge script for blocks at the moment that will construct the header proof for a pre-Capella block and then push to the client though we have semi-functional examples here for a post-merge block. An ideal solution would be a standalone script that does something like the following:

• Accept a block range as a CLI parameter
• Pull those blocks from mainnet JSON-RPC
• Second step - for post merge blocks, retrieve the corresponding Beacon Blocks from a beacon node
• Pull the appropriate Epoch Accumulators and/or Historical Batches from portal-accumulators
• Construct the header proofs and pipe to Ultralight

There is a utility method for constructing preMergeHeaderProofs and the process for constructing post-merge proofs can be found in the postMergeHistoryBridge script noted above.