feat: INF-3543 Align HTTPRoute BackendRefs With Rollout Services

[jmpalomares]

Fix Envoy Gateway HTTPRoute backendRefs to honor Argo Rollouts by redirecting Service targets to *-rollout when rollouts are enabled (including extraServices), matching _ingress.tpl behavior.

1. _httproutes.tpl: Builds a rollout services map from global argoRollout and extraServices, then rewrites matching backendRefs with the -rollout suffix.

2. _ingress.tpl: Applies the same rollout services map pattern, rewriting both custom (.backend) and default backend service names to target *-rollout when applicable.

3. _backendtrafficpolicy.tpl (new): Optional, per-route BackendTrafficPolicy CRD.
   Supports spec or inline fields; defaults targetRefs to the HTTPRoute when not provided.

4. _clienttrafficpolicy.tpl (new): Optional, per-route ClientTrafficPolicy CRD.
   Same shape and defaults as BackendTrafficPolicy.

Test:

Tested rendering the yaml files using flask-blueprint-app

Scenario	HTTPRoute	Ingress
argoRollout disabled	flask-blueprint-app	flask-blueprint-app
argoRollout enabled	flask-blueprint-app-rollout	flask-blueprint-app-rollout
extraService worker (rollout on)	flask-blueprint-app-worker-rollout	flask-blueprint-app-worker-rollout
extraService api (rollout off)	flask-blueprint-app-api	flask-blueprint-app-api

Templates correctly:

• Append -rollout to the main service when global rollout is enabled
• Append -rollout to extraServices that have their own argoRollout.enabled: true
• Leave services unchanged when rollout is disabled

https://parcellab.atlassian.net/browse/INF-3543
https://parcellab.atlassian.net/browse/INF-3539

[kpplis]

hope you tested it :)