Remove aggregation of issuance events by day.

[badgley]

Currently, we aggregate all credits issued for i) a specific vintage on ii) a specific day.

However, it's possible that credits within a single vintage year might carry different certifications / tags (see #117).

@andersy005 do you recall why we added this aggregation? I think it may have had to do with some previous approach for tracking transactions through time? Based on feedback we've received, it seems like our treatment might introduce a subtle error. If possible, we should remove this aggregation — or at the very least better justify why we need this aggregation step.

As an initial step, it would be helpful to assess what, if any, downstream effects removing this aggregation might cause.

[andersy005]

@andersy005 do you recall why we added this aggregation? I think it may have had to do with some previous approach for tracking transactions through time?

yeah, we wanted a way to assign a unique ID (serial number) to each transaction so we could track them more easily in the database. the idea was to harmonize the data because issuance transactions didn't have a unique ID before, while retirements already did via the serial number from registries

[andersy005]

As an initial step, it would be helpful to assess what, if any, downstream effects removing this aggregation might cause.

there's a chance i don't fully remember why we added the aggregation. so +1 for digging into the ramifications of removing it