Port ET with millisecond precision (from ECM MR 803)

Xiang Lirequested to merge
XiangLi/VVCSoftware_VTM:xlxiangli/vtm_enctime into master

I ported the MR from ecm/ECM!803 (merged). It was claimed that with the MR, the encoding runtime can be calculated more accurately for parallel encoding.

Merge request reports