expose last update block number + tx index + log index in records returned in snapshot + stream

[frolic]

possibly also tx hash (maybe already exposed in stream?)

this would let us do some more interesting stuff in store sync like smarter chunking based on logs in a tx (currently it can split the logs in a tx, which leads to indexer issues like we saw in dust)

[frolic]

even just returning last update block number for a record would let us expose this in the snapshot (rather than assuming every record is latest block), then we could allow for sort of "paginated" snapshots or ways to resume if hydrating from a snapshot fails