Adds the test "should be able to pull image from docker hub [WindowsOnly]",
which will pull a Windows busybox image from dockerhub. Since it is busybox,
the same command will also work for this image.

The busybox image is currently used in other E2E tests, so the image should
already be prepulled on the nodes. Additionally, the image has a manifest list
for Windows Server 1803 and Windows Server 2019, and future versions will be
added to it.