add controller-driven kube-vip load balancer for K3S_BASE clusters

[naiming-zededa]

Description

This PR implements controller-driven Kubernetes LoadBalancer services
for CLUSTER_TYPE_K3S_BASE in eve-k.

 - pkg/pillar/types/clustertypes.go: Add LBInterfaceConfig (interface +
   CIDR string) and LBInterfaces []LBInterfaceConfig to both
   EdgeNodeClusterConfig and EdgeNodeClusterStatus.
  - pkg/pillar/cmd/zedagent/parseconfig.go: Parse LoadBalancerService
    from the controller proto and populate
    EdgeNodeClusterConfig.LBInterfaces (K3S_BASE only; first
    interface/CIDR entry applied).
  - pkg/pillar/cmd/zedkube/clusterstatus.go: Relay LBInterfaces from
    EdgeNodeClusterConfig into EdgeNodeClusterStatus on the bootstrap
    node only; non-bootstrap nodes publish an empty list so they do not
    trigger kube-vip setup.
  - pkg/pillar/dpcmanager/dns.go: Filter kube-vip VIPs out of
    DeviceNetworkStatus.AddrInfoList using the LBInterfaces CIDR range,
    preventing VIPs from being used as source addresses for
    controller-bound traffic.
  - pkg/kube/cluster-init.sh: Add check_kubevip_lb loop that reads
    EdgeNodeClusterStatus JSON each iteration and calls kubevip-apply.sh
    or kubevip-delete.sh when the LB config changes. Persists
    last-applied state to avoid redundant re-applies across restarts.
  - pkg/kube/kubevip-apply.sh / kubevip-delete.sh: Scripts to
    install/remove the kube-vip DaemonSet and kube-vip-cloud-provider
    Deployment, configuring the IP pool via a kubevip ConfigMap.
  - pkg/kube/kubevip-ds.yaml: kube-vip DaemonSet manifest (ARP mode,
    control-plane nodes).
  - pkg/kube/config.yaml: Disable k3s built-in ServiceLB (servicelb) and
    Traefik for K3S_BASE — kube-vip replaces ServiceLB; users bring
    their own ingress.
  - pkg/pillar/docs/zedkube.md: Document the feature with an overview
    diagram, data-flow, EVE-API proto, and DeviceNetworkStatus filtering
    notes.

PR dependencies

How to test and validate this PR

Create a native orchestration type cluster on EVE devices, and in the controller config the enabling of 'loadbalancing'
for the cluster. Specify the interface and IP prefix of the LB.

In the kubernetes side, user specify the helm/yaml definition of App and Service with type of 'loadbalancer'. Verify
the service has the IP address allocated on the interface for this service, and endpoint created for the App.

User the specify client to access that ip address and port. and verify when one device is down, the IP is reallocated
to another device of the cluster, and the app is still reachable.

there are many different ways to use the LB service, see examples in pkg/pillar/docs/zedkube.md for detail

Changelog notes

add controller-driven kube-vip load balancer for K3S_BASE clusters

PR Backports

Checklist

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• I've added the proper documentation
• I've tested my PR on amd64 device
• I've tested my PR on arm64 device
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[zedi-pramodh]

Do we publish this LBPoolStatus in any eve pub/sub calls for collect info ?

[naiming-zededa]

this LBPoolStatus is published by zedkube in KubeUserServices, so it is part of the collectinfo.