gRPC Frontend does not set `xrd::Response` type in case of error

Currently a failed physics workflow call will only return an grpc status indicative of the error, but it might make sense to also fill in the xrd::Response

assigned to @kskovola

mentioned in merge request dss/eos!261 (closed)

mentioned in merge request !847 (merged)

mentioned in commit be593174

closed with merge request !847 (merged)

mentioned in commit dfa9ffac