Default ownerReference for NodeFeature should be Node

**What would you like to be added**:

I think the default/out-of-box behavior when NFD is installed should be that the `NodeFeature` CRs should have their owner reference set to `v1.Node` object.

**Why is this needed**:

The rationale is basically summarized at https://ahmet.im/blog/nfd-incident/. Basically, any other alternative is worse:

* **[Owner is DaemonSet Pod (current default)](https://github.com/kubernetes-sigs/node-feature-discovery/blob/4f24a38ad48e364b4164baf01d81a2967e59e2c7/pkg/nfd-worker/nfd-worker.go#L256-L278)**: Means your node labels are gonna get cleared during a rolling update of daemonset. No-go for a lot of installations that want to guarantee labels will always be there.
* **[No owner (configured via a CLI flag)](https://github.com/kubernetes-sigs/node-feature-discovery/blob/4f24a38ad48e364b4164baf01d81a2967e59e2c7/cmd/nfd-worker/main.go#L126-L127):** Means you'll leak NodeFeature CRs (though the controller can totally clean these up during periodic resyncs if it has that logic in nfd-gc).

**Parenting to v1.Node** has the following advantages:
- NodeFeature resource doesn't get randomly deleted by the controller (and cause incidents like the one linked above) and its lifespan is now tied to Node itself.
- Eliminates the need for nfd-gc as Kubernetes garbage collector in kube-controller-manager would now handle the removal.

I can't think of any downsides to having a single ownerReference set to the Node object.