Reduce latency for MongoDB streaming in high transactions/second environments

The connector uses a tryNext call to the MongoDB Cursor which is created using a TailableAwait type configuration. The documentation for this cursor type seems to indicate that MongoDB will apply its own "pause" mechanism if the batch it returns is empty to avoid high cpu utilization for loops that use this non-blocking IO strategy. If that's indeed the case, the Metronome isn't required and only adds additional latency that could be eliminated for high transactions/second environments to reduce event latency.

See conversation https://gitter.im/debezium/user?at=5f9c3715d5a5a635f28eb78e