Deprecate Support for `ingress.className` in [`alb`, `gce`]

[ranchodeluxe]

Goal

nginx is the best way to have agnostic support across all cloud providers as already supported for GCP and AWS here. In the future support for Azure and Open Telekom Cloud will be added. Let's Encrypt and the k8s plugin jetstack/cert-manager should handle all TLS needs

Action Items

• - get rid of all Application Load Balancer (or whatever they are called across cloud providers) direct support in templates
• - remove docs and tests

[ranchodeluxe]

handled here: #71