rpm: opensuse: extract the version of zypper
rpm: opensuse: use zypper download if available

Use the "download" command of zypper, if it is >= 1.9.14.
tests: add OpenSUSE checks in test-harder

Basically copied from the redhat ones.
rpm: opensuse: disable recommends with old zypper

When using zypper < 1.9.14, disable the recommends when "installing"
packages locally, reducing the number of packages being downloaded.