Aggregate continued queries without an explicit group have incorrect results

[hazefully]

For a query with an aggregate function and no explicit group such as SELECT COUNT(*) FROM T that ends up being planned as a RecordQueryStreamingAggregationPlan, partial aggregation results do not get stored in continuations correctly. As a result, the final result retrieved from the final continuation will not contain the partial results from previous executions.

For example, if T has 13 rows and no aggregate indexes defined, the query will be planned as SCAN(<,>) | MAP (_ AS _0) | AGG (count_star(*) AS _0) | ON EMPTY NULL | MAP (coalesce_long(_._0._0, promote(0l AS LONG)) AS _0). If we assume an enforced scan row limit of 5, we expect the final result after 2 continuations to be 13, but instead the result is 1, which is the number of records scanned in the third scan.