fix: enforce defaults in OCP form view

[tumido]

Description of the change

OCP Console is acting strangely when we want to default to [], it assumes it's null and pulls data from the schema. This PR should ensure the schema is always consistent with default values in the chart, including values for subcharts.

Existing or Associated Issue(s)

Fixes: #151

Additional Information

https://github.com/janus-idp/helm-backstage/assets/7453394/e2709f02-0665-4954-ac15-2beb327e37ab

Checklist

• [x] Chart version bumped in Chart.yaml according to semver.
• [x] Variables are documented in the values.yaml and added to the README.md. The pre-commit utility can be used to generate the necessary content. Use pre-commit run -a to apply changes.
• [x] JSON Schema template updated and re-generated the raw schema via pre-commit hook.
• [x] List tests pass for Chart using the Chart Testing tool and the ct lint command.

[tumido]

cc @kadel

[tumido]

CI failing due to https://github.com/janus-idp/backstage-showcase/issues/813 please retrigger once new build for next finishes.