Provide more info when a stream fails

[abourget]

Goal: Improve Substreams DevEx

When a stream stops, you get an error with the final message, but the engine drops the logs produced by the failed module, which might be precious for debugging.

Here are suggested solutions:

• In dev mode, send all the info for the block we have, before shutting down the connection.. so we have logs and context of failure, in addition to the failed message.
• In production mode, we should print at least all the logs of the current output module, alongside the error message.. either in a header, or directly in the error string.