Notable changes:
  * Support for -max-threads and CIPD_MAX_THREADS to unzip in parallel.
  * Bug fix for crbug.com/1029955.

R=tandrii@chromium.org

Change-Id: If309f6bbc6bab24d88be465fc7fe7ea7b9ee40b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1949017Reviewed-by: Andrii Shyshkalov <tandrii@google.com>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>