Allow Nyl to better understand Helm hooks #25

helm template simply outputs all hook manifests, unless we pass --no-hooks. Since helm template does not reach out to the cluster, it can't tell if it's a fresh install or upgrade so it will always assume both.

Since we're not allowing helm install to create a secret to track the Helm release metadata to make that decision, I think it's okay that we don't allow helm template to reach out to the cluster. However, Nyl already has some aspects that require it to talk to the cluster (the lookup() function and finding the values to pass to the helm template --api-versions flag), so we might as well try and find a good mechanism for Nyl to track the installation state of the chart.