This PR implements protobuf streaming to handle large module files by:
1. **Streaming large payloads**: When module files exceed the 4MB limit,
they're streamed in chunks using a new UploadFile RPC method
2. **Database storage**: Streamed files are stored in the database and
referenced by hash for deduplication
3. **Backward compatibility**: Small module files continue using the
existing direct payload method
My understanding is that `io.EOF` is eventually expected, so logging it
as an error may be confusing. For other errors we should definitely
WARN.
```
[info] provisionerd-ip-172-31-12-44-14: recv done on Session session_id=22b9ef8a-9cd6-4188-98e0-573a50d724cc error=EOF
```
This change reduces the CPU consumption of --help by ~50%.
Also, this change removes ANSI escape codes from our golden files. I
don't think those were worth the inability to parallelize golden file tests and
global state fragility.
Steven Masley