The ReclockOperator is responsible for observing progress in the FromTime domain and
consume messages from a ticker of progress in the IntoTime domain. When the source frontier
advances and the ticker ticks the ReclockOperator will generate the data that describe this
correspondence and write them out to its provided remap handle. The output generated by the
reclock operator can be thought of as Collection<G, FromTime> where G::Timestamp is
IntoTime.