* fix issue of  https://github.com/kubeovn/kube-ovn/issues/1151

When kube-ovn-controller starts in a cluster with lots of services, the previous empty match log will flood the screen:
```
I0208 00:31:03.804692       1 network_policy.go:789] match svc is []
I0208 00:31:03.804757       1 network_policy.go:789] match svc is []
I0208 00:31:03.804775       1 network_policy.go:789] match svc is []
I0208 00:31:03.804785       1 network_policy.go:789] match svc is []
I0208 00:31:03.804793       1 network_policy.go:789] match svc is []
I0208 00:31:03.804802       1 network_policy.go:789] match svc is []
I0208 00:31:03.804810       1 network_policy.go:789] match svc is []
I0208 00:31:03.804821       1 network_policy.go:789] match svc is []
I0208 00:31:03.804832       1 network_policy.go:789] match svc is []
```

* feat: Replace command health check with k8s tcpSocket check

* skip the missing of kube-dns

* skip missing of kube-dns when checking

fix: check if taint exists before un-taint

When retry install, un-taint for not exist taint will fail

```
kubectl taint node kube-ovn-control-plane node-role.kubernetes.io/master:NoSchedule-
error: taint "node-role.kubernetes.io/master:NoSchedule" not found
Makefile:180: recipe for target 'kind-install-underlay-ipv6' failed
make: *** [kind-install-underlay-ipv6] Error 1
Error: Final attempt failed. Child_process exited with error code 2
```

add policy route for distributed subnet in default vpc

ci: add retry to fix flaky test

transfer IP/route after OVS startup

check static route conflict

set up tunnel correctly in hybrid mode

delete unused constant

add metric for ovn nb/sb db status

fix clusterrole in ovn-ha.yaml

add gateway check after update subnet

we should first see if a condition is not going to be met

add judge before use slices index

prevent multiple namespace reconcile

fix: validate statefulset pod by name

Some controller (e.g. vcluster) will add pod owner reference to statefulset, however this pod is not controlled by statefulset controller, we should not treat it as a statefulset pod.

add back centralized subnet active-standby mode

fix golang and base image versions

support to add multiple subnets for a namespace