Add cluster name to kiali URL

What

The code change updates the Kiali ingress hostname to include the cluster name. This will allow Kiali to be accessed using a more specific URL, which will make it easier for users to identify the correct Kiali instance they are trying to access.

Eg:

• https://kiali.pre-gitlab-gke.pre.gitlab.net
• https://kiali.gstg-gitlab-gke.gstg.gitlab.net (GSTG Regional GKE Cluster)
• https://kiali.gstg-us-east1-b.gstg.gitlab.net (GSTG Zonal GKE Cluster - us-east1-b AZ)

Why

Each kiali instance can connect to only one istio mesh. Therefore we need to make sure we are connecting to the right kiali instance to visualize the corresponding istio service mesh.

Related Issue: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/24159

Flux Diff:

➜  components git:(mchacon-kiali-region) flux diff kustomization flux-components-kiali --path ./kiali
✓  Kustomization diffing...
► VirtualService/istio-system/kiali drifted

metadata.generation
  ± value change
    - 1
    + 2

spec.hosts.0
  ± value change
    - kiali.pre.gitlab.net
    + kiali.pre-gitlab-gke.pre.gitlab.net

⚠️ identified at least one change, exiting with non-zero exit code