[Data Service] Implement simple upstream transaction filtering

There are two types of transaction filtering we will support in the future:
1. Per stream configuration: The downstream declares what txns they want to receive.
2. Global configuration: At the data service level we refuse to include full txns for all streams.

This PR implements the second of these, using @CapCap's work here:
aptos-labs/aptos-indexer-processors#398.

Rather than not sending txns at all if they match the blocklist filters, we just omit the writesets and events. Not sending the txns entirely would cause issues with processors, which today assume that they will receive all txns.