feat(graphql): provide states with merkle proof

[moreal]

Users cannot know whether the node lies about states because it doesn't provide Merkle proof. For example, at #1000 block, the state is "YES" but the headless operator can lie it as "NO" if they want.

But users can verify it if there is a Merkle proof and can access block data (in detail, state root hash). You can see the Merkle proof explanation at https://ethereum.org/en/developers/tutorials/merkle-proofs-for-offline-data-integrity/.