Change numberOfCorrelatedDataProducts to represent the number of measurement...

Change numberOfCorrelatedDataProducts to represent the number of measurement sets in the task abd not be hardcoded to one

assigned to @tmillenaar

This change only sums the nr of items in the task. If the task is split over multiple machines, the sum cannot be know from the pipeline perspective. Hence the fix will be done on atdb level, not on pipeline level. ATDB ticket: https://support.astron.nl/jira/browse/SDC-1590

closed