View results can be out of order when includeDocs, due to flatMap

View result with includeDocs = true trigger an additional operation for each row (fetching the document). Depending on the duration of each fetch, it could change the order in which the results are emitted because the code uses flatMap (which will emit the rows as the documents arrive, not in initial order).

It should be made so that the rows are emitted in view order, but without sacrificing too much of the flatMap performance.