Add Gateway API HTTPRoute support to Helm chart

[lexfrei]

Summary

Adds Gateway API HTTPRoute support to Kubernetes Dashboard Helm chart as a modern alternative to traditional Ingress.

Motivation

• Gateway API reached GA status (v1.0+, October 2023)
• Provides vendor-neutral, portable ingress configuration
• More flexible routing capabilities compared to Ingress
• Supported by major Gateway controllers (Cilium, Istio, Traefik, Kong, Envoy Gateway)

Changes

• Added templates/networking/httproute.yaml template
• Added app.httproute configuration section in values.yaml
• Updated Chart version to 7.14.0
• HTTPRoute uses existing Kong proxy backend

Testing

• helm template renders correctly
• helm lint passes with no errors
• Tested in local cluster with Cilium Gateway API
• HTTPRoute successfully created and accepted by gateway controller
• Kong proxy service correctly referenced as backend

Configuration Example

app:
  httproute:
    enabled: true
    parentRefs:
      - name: my-gateway
        namespace: gateway-system
        sectionName: https
    hostnames:
      - dashboard.example.com
    tls:
      enabled: true

Closes #10384

[k8s-ci-robot]

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