[Envoy] Replace LUA-Cookie-Match with HTTPRouteFilter

In Envoy Gateway 1.6.0 There wasn't a good way to check for the existence of a cookie. Therefore we had to implement a LUA filter for Immich https://github.com/ThomasBuchinger/prod-gitops/blob/main/gitops/immich/external-route.yaml#L111

Envoy Gateway 1.7.0 added a native matcher for Cookies: https://gateway.envoyproxy.io/docs/api/extension_types/#httpcookiematch