Helm chart QoL improvements

[vordimous]

Describe the desired outcome from the user's perspective
Helm charts can have a wide range of usage patterns that are exposed through the values.yaml file. There are some common components and helm templates to add that can help deploy zilla in situations devs are more familiar with.

ENV vars are the main wait to dynamically modify the zilla.yaml and giving the user more options to configure them will be much more helpful. If we can just replicate what the Grafana helm chart has it would make any deployment pattern easier.

Acceptance criteria

• use the structure of chart templates and values found in the default helm create zilla template
  • unique name use values generated in the _helpers.tpl file
  • keep optional ingress and service account
  • keep values.yaml structure and similar as possible with comments
• remove license text from the NOTES.txt file
• add comments in values.yaml for added parameters
• add more ways to configure ENV vars

[vordimous]

moved HTTP/2 feature to its on ticket

• Helm chart option for handling HTTP/2 behind an Ingress controller #896