HPCC-9491 - Move CFileChangeWriteLock,avoid refs to Owned

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Changes following review

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Merge pull request #4524 from jakesmith/hpcc-9491b

HPCC-9491 - Move CFileChangeWriteLock,avoid refs to Owned

Reviewed-By: Gavin Halliday <gavin.halliday@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>