Improve ingress manifests

Currently we can only deploy a new nginx-ingress instance. This is not ideal, especially when your using another ingress or already have nginx-ingress. Users should be able to just provision a single ingress manifest where they can define things such as annotations and tls certificates.

Locate the chart templates responsible for provisioning the nginx-ingress instance and read how ingress values are currently configured. Determine how a single configurable ingress manifest should expose annotations and TLS certificates while allowing an existing ingress controller, then verify the rendered manifests cover those cases.

Written by the indexing model from the issue text.