Merge pull request #346 in CASA/casa6 from CAS-13360 to master
* commit 'bd94c94ca4091c7869aec3cc196735324fc42d12':
Use the SPW and polID from the msiter to improve performance
Cache the spw and pol for determineChannelSelection in the row loop under row blocking
Read the spectral windows and polarizations before the loop on rows
Rename test_eq->func_test_eq to avoid issues with pytest
test_flagdata: Unflag test MS before running flagdata and check for total flagged rows
Improve VisibilityIteratorImpl2 unit tests with row blocking
Add test to flagdata that exercises an MS with decreasing number of rows in subsequent chunks
Initialize the row numbers to allow the channel selection to work properly
