fix(anvil): return error for eth_getLogs with unknown blockHash instead of empty

[spalladino]

Return a JSON-RPC error (-32000 "unknown block") when eth_getLogs is called with a blockHash that doesn't resolve to a known block, instead of silently returning an empty array. This aligns with how geth and other clients behave:

$ curl -s -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_getLogs","params":[{"blockHash":"0x0000000000000000000000000000000000000000000000000000000000000001"}],"id":1}'  $RPC_URL

{"jsonrpc":"2.0","id":1,"error":{"code":-32000,"message":"unknown block"}}

$ curl -s -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"web3_clientVersion","params":[],"id":1}' $RPC_URL

{"jsonrpc":"2.0","id":1,"result":"Geth/v1.17.2-stable-be4dc0c4/linux-arm64/go1.26.1"}

See also paradigmxyz/reth#7371

Code written with Claude.

[spalladino]

Thank you all for the fast response 🚀