Merge remote-tracking branch 'origin/candidate-3.10.2' into candidate-3.10.x

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
HPCC-8547 - Interleaved mixed width subfiles exposing mapSubPart bug

mapSubPart was testing the wrong subfile when iterating through
parts/subs to determining which subfile and part the logical part index
referred to.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
HPCC-8596 Problems dealing with CSV headers in mixed width supers

When have read all local parts, need to check unsent part header
counts from previous node.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #3849 from jakesmith/mapSubPart

HPCC-8547 - Interleaved mixed width subfiles exposing mapSubPart bug

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #3850 from jakesmith/supercsv-header

HPCC-8596 Problems dealing with CSV headers in mixed width supers

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Merge remote-tracking branch 'origin/candidate-3.10.x' into candidate-3.10.2

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>