Add owner object info to Kubernetes metadata

[exekias]

This change adds object name for the Pod owner (if any) when enriching
with kubernetes metadata.

This information is really useful when mapping running containers to
their creator workload.

Resulting metadata will now include the name of the Deployment, ReplicaSet or StatefulSet who created the Pod (if any), ie:

{
  "kubernetes":{
    "container":{
      "name":"kube-state-metrics"
    },
    "labels":{
      "k8s-app":"kube-state-metrics",
      "pod-template-hash":"2035844717"
    },
    "namespace":"kube-system",
    "node":{
      "name":"minikube"
    },
    "pod":{
      "name":"kube-state-metrics-6479d88c5c-5b6cl"
    },
    "replicaset":{
      "name":"kube-state-metrics-6479d88c5c"
    }
  }
}

[ruflin]

@exekias Should we add this field to ECS?

[exekias]

maybe, let's figure out if it makes sense once released

[nic-6443]

Why remove config for labels and annotations?

[exekias]

This change only moved them around in the code (while didn't change how they worked): https://github.com/elastic/beats/pull/7231/files#diff-f7068996b1041934b4fa71b630725b55R20