Create funding events by artifact (from onchain transactions)

[ccerv1]

What is it?

Currently we only aggregate funding events at the to/from project level. This is because we don't have artifact (eg, wallet) level data for many of the funders and we don't confirm receipt onchain. We should consider supporting actual tracking of onchain transactions to the artifact level, at least to_artifact_name. (Some funders might use fancier payment mechanisms, eg Optimism -> Superfluid) that will make it harder for us to track all the way back to them.