Add support for offchain public batch attestations

[web3pm]

We have a number of attestation schemas on mainnet ethereum that would be nice to be able to make batch offchain public attestations for using EAS and this tool.

EAS SDK supports the signOffchainAttestation command so it would be nice to have a toggle that allows the user to submit and generate a bunch of offchain attestations.
(ref: https://docs.attest.sh/docs/developer-tools/eas-sdk#creating-offchain-attestations)

It would be nice if these were automatically pinned to ipfs and indexed with their indexer a la https://github.com/ethereum-attestation-service/met-irl/blob/26b0499b57f793418ea34ae19e32793a464963ad/src/utils/utils.ts#L220

[kristoferlund]

@web3pm I started to read up on offchain attestations. Haven't looked to closely at them before. Seems like EAS SDK don't provide a way to pin the signed attestations to IPFS. Taking care of that is easy though. Did you see if there was a way to notify the EAS indexer of the existence of the created attestations?

Posted this question in the TG as well:

Does anyone know, if I create a bunch of offchain attestations and pin them myself to IPFS, is there a way to programmatically notify the EAS indexer of the existence of these attestations so they get picked up and displayed in the explorer?