feat: Transform Agent extra pod labels

[jsirianni]

Description of Changes

The chart supports extraPodLabels for Bindplane and Prometheus pods, but not Transform Agent. This PR addresses that. The transform agent extra labels are implemented the same as Bindplane / Prometheus.

Testing

I included this config snippet in my values file.

transform_agent:
  extraPodLabels:
    user: joe
    repo: bindplane-op-helm

When inspecting the deployed transform agent pod, I see the following labels. The last two are the extra labels added by the values file.

apiVersion: v1
kind: Pod
metadata:
  labels:
    app.kubernetes.io/component: transform-agent
    app.kubernetes.io/instance: bindplane
    app.kubernetes.io/name: bindplane-transform-agent
    app.kubernetes.io/stack: bindplane
    pod-template-hash: 74cb87887d
    repo: bindplane-op-helm
    user: joe

Please check that the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• CI passes
• Changes to ports, services, or other networking have been tested with istio