cmd/k8s-operator: ensure HA Ingress can operate in multicluster mode.
Update the owner reference mechanism so that:
- if during HA Ingress resource creation, a VIPService
with some other operator's owner reference is already found,
just update the owner references to add one for this operator
- if during HA Ingress deletion, the VIPService is found to have owner
reference(s) from another operator, don't delete the VIPService, just
remove this operator's owner reference
- requeue after HA Ingress reconciles that resulted in VIPService updates,
to guard against overwrites due to concurrent operations from different
clusters.
Updates tailscale/corp#24795
Signed-off-by: Irbe Krumina <irbe@tailscale.com>