Consuming messages from each partition separately

**Feature request**

To address https://github.com/Blizzard/node-rdkafka/issues/1063 we've ([withthegrid](https://github.com/withthegrid/)) created a PR (https://github.com/Blizzard/node-rdkafka/pull/1101) on https://github.com/Blizzard/node-rdkafka. Would you be willing to merge a similar PR to this repo which adds the same functionality? 