Optional Daemonset deployment

[ganey]

I noticed it isn't currently possible to deploy this as a kube Daemonset.

The changes needed are quite small, and obviously we default to the current behaviour.

Using a replica count higher than the number of nodes seems counter productive based on documentation here: https://developers.cloudflare.com/cloudflare-one/connections/connect-networks/deploy-tunnels/system-requirements/#recommendations

Multiple pods per node would then be fighting for the same ephemeral ports, so using a daemonset we can cap the cloudflared at 1 per node.