feat: Add hostAliases to the controlPlane statefulSet pod configuration

[flomedja]

What issue type does this pull request address? (keep at least one, remove the others)
/kind feature

What does this pull request do? Which issues does it resolve? (use resolves #<issue_number> if possible)
resolves ENG-8076
resolves #2500

Please provide a short message that should be published in the vcluster release notes

• Add support for configuring hostAliases in the control plane StatefulSet

What else do we need to know?

---

Note

Enables configuring custom /etc/hosts entries for control plane pods.

• Template: renders spec.hostAliases when controlPlane.statefulSet.hostAliases is set in statefulset.yaml
• Values/Schema: adds controlPlane.statefulSet.hostAliases (array of HostAlias) with default [] and defines $defs.HostAlias
• Go config: adds HostAliases []corev1.HostAlias to ControlPlaneStatefulSet
• Tests: adds unit test to validate hostAliases rendering

^{Written by Cursor Bugbot for commit cf51de4. This will update automatically on new commits. Configure here.}

[johannesfrey]

lgtm