Post capella block verification

[acolytec3]

• Adds parsing of blocks from era files and better error handling
• Adds a new post capella bridge script for constructing block header proofs rooted in HistoricalSummaries
• Allow verification of post-capella headers based on having the HistoricalSummaries present
• Cleans up header verification logic in HistoryNetwork.validateHeader
  • Verify that header data constructs a header with the same hash as the provided block hash
  • Switch header proof verification utilities to return boolean values instead of throwing

[ScottyPoi]

Approving with minimal feedback. Some comments in the code explaining what is happening would be helpful.

[ScottyPoi]

does the ethjs bytesToBigInt function not work here? It has a littleEndian: boolean = false parameter

[acolytec3]

When I switch to bytesToBigInt, my tests start failing so something's awry. Will research a bit more.