Parallelize IPFS Requests for App Data

[nlordell]

This iterative async block of code could probably be a batch request.

    for hash in uninitialized_app_data_hashes.iter() {
        download_referral_from_ipfs_and_store_in_referral_store(db.clone(), *hash).await?;
    }

cf referral_maintenance.rs

Original issue gnosis/gp-dune-bridge#59 by @bh2smith

[josojo]

Yes, this should be doable. Just a word of warning: When I was first implementing it, I had to fight with rate limitings. If we parallelize it, there is a risk that this will reappear

[bh2smith]

To avoid the rate limiting (maybe) You can put a cap on the size of the batches.