feat(tlsroute): Add TLSRoute configuration for Argo CD server

[xavier-re]

Motivation

Sometimes we want to have end-to-end tls encryption. Argocd server has already a https listener, so if we are using gateway api (recommended after ingress nginx retirement), we need a TLSRoute to route tls traffic up to the argocd endpoint.

What this PR does / why we need it:

This PR adds support for Gateway API TLSRoute resource to the Argo CD Helm chart. TLSRoute enables TLS passthrough or termination at the Gateway level, allowing traffic routing based on the hostname (= SNI = Server Name Indication) without requiring the Gateway to decrypt the traffic. This is particularly useful for scenarios where:

• TLS termination needs to happen at the backend service (passthrough mode)
• Gateway-based routing is required for TLS traffic
• Integration with Gateway API-compatible ingress controllers like Envoy Gateway, Istio, or Cilium

Special notes:

• TLSRoute support is marked as EXPERIMENTAL (like HTTPRoute and GRPCRoute)
• Requires Gateway API CRDs to be installed in the cluster
• The API version used is gateway.networking.k8s.io/v1alpha2 (standard for TLSRoute)
• The implementation dynamically selects the correct service port (HTTP 80 or HTTPS 443) based on the server.insecure configuration
• If no custom rules are specified, a sensible default rule is created that routes to the argocd-server service

Release notes:

- Add Gateway API TLSRoute support for Argo CD server with configurable parentRefs, hostnames, and routing rules

Tests:

• Manual template rendering verification with various configurations

Checklist:

• I have bumped the chart version according to versioning
• I have updated the documentation according to documentation
• I have updated the chart changelog with all the changes that come with this pull request according to changelog.
• Any new values are backwards compatible and/or have sensible default.
• I have signed off all my commits as required by DCO.
• I have created a separate pull request for each chart according to pull requests
• My build is green (troubleshooting builds).