Unwrap server exception

At the moment a server exception is wrapped in a client exception with some grpc wrappings as well. It would be nice if the exception on the server was the only thing the user was bothered with.

Start by tracing how server exceptions are wrapped through the gRPC server and client layers; the issue names no files or tests. Done means a user receives the server exception directly, without the client exception or additional gRPC wrapping.

Written by the indexing model from the issue text.