index Gitcoin Attestation Network

[thelostone-mc]

Close PAR-407

This adds 2 new tables

• Attestations: which indexes the summary and metadata of the actual cart / checkout
• AttesationTxn : which indexes all the attesation txn and which chain the attesation lives on

There is also a fk to the donations table which lets you list donations for a given a given AttesationTxn and also check if a donation has an associated attestation uid

{
  attestationTxns {
    chainId
    attestation {
      uid
    }
    donations {
      id
    }
  }
}

{
  donations {
    id
    attestationTxnsByTxnHashAndChainId {
      attestationUid
    }
  }
}

[linear]

PAR-407 Spike / Implement need to update indexer to store attestations for faster queries

[hussedev]

LGTM!