Support getting NTFS valid data length from non-resident attribute list
Support getting NTFS valid data length from non-resident attribute list

(cherry picked from commit d698909fda2f5b6173d8cc26883db2c2459bd8d6)

uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend