feat(openfga): Allow extra labels specific to pods

[grimly]

This PR provides the ability to add labels to openfga pods.

Description

Some mechanisms such as Network Policies or Webhooks uses the concept of LabelSelector. This PR adds a podExtraLabels value next to the podAnnotations so that extra labels can be added to the openfga pods.

This change was validated through snapshot testing in an internal fork.
There is no testing framework in place here. Providing the mentioned snapshot testing framework is out of this PR's scope so I won't check the last box.

References

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: grimly / name: Michel TURPIN (f937d01)