Add Block Header

[patrick-ogrady]

Generate a block hash over a root of included/successful transactions instead of the concatenation of all transactions:

• [chain] Hash Block Based on Hash Trie of Transactions + State Root + Results Root + Warp Outputs Root #412
• [chain] Add tx root to each block header #503
• Bloch hash generation by merkle trie root of transactions, results and state root #689

This will allow anyone to prove inclusion against a header (useful for lite clients).

[github-actions]

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