Currently the traffic mirroring library is used by the indexer and by the forknet tool that mirrors traffic from mainnet to forknet.
Indexer need to crash if blocks are not found, while the forknet traffic generator does not need to and ca work by skipping the error.

The ask is to move the panic and propagate the error out of the mirroring library.
This unblocks forknet for stateless validation testing.