update codec to allow reuse buffers

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

options.go

@@ -0,0 +1,18 @@
+package proto
+
+import (
+	codec "go.unistack.org/micro/v3/codec"
+	"google.golang.org/protobuf/proto"
+)
+
+type unmarshalOptionsKey struct{}
+
+func UnmarshalOptions(o proto.UnmarshalOptions) codec.Option {
+	return codec.SetOption(unmarshalOptionsKey{}, o)
+}
+
+type marshalOptionsKey struct{}
+
+func MarshalOptions(o proto.MarshalOptions) codec.Option {
+	return codec.SetOption(marshalOptionsKey{}, o)
+}