Add WebUI component to Chart

[ccremer]

Summary

• Follow up of WebUI: Add Proxy support for the Kubernetes API #179
• Adds a new parent group webui
• Adds Ingress for Webui
• The Kubernetes API can be accessed by having a Service with ExternalName, provided it has a valid certificate and allows CORS.
• Alternatively, the Proxy from WebUI: Add Proxy support for the Kubernetes API #179 can be enabled

Checklist

• Categorize the PR by setting a good title and adding one of the labels:
  kind:bug, kind:enhancement, kind:documentation, kind:change, kind:breaking, kind:dependency
  as they show up in the changelog
• PR contains the label area:chart
• PR contains the chart label, e.g. chart:clustercode
• Variables are documented in the values.yaml using the format required by Helm-Docs.
• Chart Version bumped if immediate release after merging is planned
• I have run make chart-docs
• Link this PR to related code release or other issues.