I added new functions to winutil to obtain the state of a service and all
its depedencies, serialize them to JSON, and write them to a Logf.
When tstun.New returns a wrapped ERROR_DEVICE_NOT_AVAILABLE, we know that wintun
installation failed. We then log the service graph rooted at "NetSetupSvc".
We are interested in that specific service because network devices will not
install if that service is not running.
Updates https://github.com/tailscale/tailscale/issues/5531
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Aaron Klotz