Persist gRPC error messages

[hedhyw]

Is your feature request related to a problem? Please describe.

Currently, Zilla only reports only status codes without text descriptions.

For example if the server responds:

status.Error(codes.NotFound, "Example description")

Zilla persists the following Kafka headers (only status, no description):

The client receives an empty description:

rpc error: code = NotFound desc =

Describe the solution you'd like
Include information about the error message.

Describe alternatives you've considered
N/A

Additional context
Probably, also relates to: #730

[jfallows]

Thanks for the feature request @hedhyw.

It definitely makes sense for us to propagate the custom status description when present for consistency.

[jfallows]

Fixed by #730.

[jfallows]

@ankitk-me Metadata is propagated but grpc status description is not yet propagated.