[FEATURE REQUEST] Add configuration option to Keycloak for PROXY_ADDRESS_FORWARDING env. variable

[GrzegorzKlankABB]

Is your feature request related to a problem? Please describe.
I would like Keycloak service to be aware of being behind HAPRoxy and inform it to use X-Forwarded-... headers for proper JWT issuer information. At the moment I manually edit keycloak stateful set to include PROXY_ADDRESS_FORWARDING environment variable.

Describe the solution you'd like
I would like Epiphany yml configuration file to have flag in auth-service application config that would translate to PROXY_ADDRESS_FORWARDING true/false value passed as environment variable to the keycloak pod. The default value can be set to false to maintain backward compatibility.

Describe alternatives you've considered

Additional context

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DoD checklist

• Changelog updated
• COMPONENTS.md updated / doesn't need to be updated
• Schema updated / doesn't need to be updated
• Feature has automated tests
• Automated tests passed (QA pipelines)
  • apply
  • upgrade
• Idempotency tested
• Documentation added / updated / doesn't need to be updated
• All conversations in PR resolved
• Solution meets requirements and is done according to design doc
• Usage compliant with license
• Backport tasks created / doesn't need to be backported

[plirglo]

OS does not matter during testing process since application works in k8s cluster.
Tested on Ubuntu with application setup:

kind: configuration/applications
title: Kubernetes Applications Config
name: default
specification:
  applications:
  - name: auth-service
    enabled: true
    image_path: epiphanyplatform/keycloak:14.0.0
    use_local_image_registry: true
    service:
      proxy_address_forwarding: true

By default proxy_address_forwarding is set to false

Configuration deployed:

[plirglo]

@przemyslavic i think we can merge this, i'm moving it to DoD, move back if you have any doubts