qga-win: implement a 'guest-get-load' command

Windows has no native equivalent API, but it would be possible to
simulate it as illustrated here (BSD-3-Clause):

  https://github.com/giampaolo/psutil/pull/1485

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Tested-by: Dehan Meng <demeng@redhat.com>
Reviewed-by: Yan Vugenfirer <yvugenfi@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
5 files changed