EDS ACK should contains all eds cluster names

[Tiger Xu / Zhonghu Xu]

What happened:

Istio can incrementally push eds, when a specific endpoints updated because of scale in/out

In this case scaling httpbin application we can see curl pilotIP:8080/debug/adsz?proxyID=kmesh |jq

The watched eds changed:

 "watches": {
        "type.googleapis.com/envoy.config.cluster.v3.Cluster": [],
        "type.googleapis.com/envoy.config.endpoint.v3.ClusterLoadAssignment": [
          "outbound|443||kubernetes.default.svc.cluster.local",
          "outbound|53||kube-dns.kube-system.svc.cluster.local",
          "outbound|9153||kube-dns.kube-system.svc.cluster.local",
          "outbound|80||sleep.default.svc.cluster.local",
          "outbound|8000||httpbin.default.svc.cluster.local",
          "outbound|15010||istiod.istio-system.svc.cluster.local",
          "outbound|15012||istiod.istio-system.svc.cluster.local",
          "outbound|443||istiod.istio-system.svc.cluster.local",
          "outbound|15014||istiod.istio-system.svc.cluster.local"
        ],
        "type.googleapis.com/envoy.config.listener.v3.Listener": []

changed to

"watches": {
        "type.googleapis.com/envoy.config.cluster.v3.Cluster": [],
        "type.googleapis.com/envoy.config.endpoint.v3.ClusterLoadAssignment": [
          "outbound|8000||httpbin.default.svc.cluster.local"
        ],
        "type.googleapis.com/envoy.config.listener.v3.Listener": []
      }

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Kmesh version:
• Others: