Add VS 2019 support to package_from_installed.py.

This CL also removes VS 2015 support.

Bug: 1006238
Change-Id: Ib05b3d211341fcd5805c3acca3bc4c0aa894831d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1823961Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Commit-Queue: Mirko Bonadei <mbonadei@chromium.org>