add grpc wrapper to extract code

Author: rekby

internal/grpcwrapper/rawtopic/rawtopicreader/stream_reader_stream_interface.go

@@ -0,0 +1,9 @@
+package rawtopicreader
+
+//go:generate mockgen -destination stream_reader_stream_interface_mock.go -package rawtopicreader -write_package_comment=false --typed . TopicReaderStreamInterface
+
+type TopicReaderStreamInterface interface {
+	Recv() (ServerMessage, error)
+	Send(msg ClientMessage) error
+	CloseSend() error
+}