DNM | WIP: PoC of sticky IPs for Kubernetes entities

[maiqueb]

What this PR does / why we need it:
This is a proof of concept of implementing sticky IP allocations for whereabouts.

Any interested party can use whereabouts to have persistent IP allocations across their workload lifecycle - e.g. KubeVirt VMs.

You indicate this whereabouts build you want to have persistent IPs for a certain allocation by specifying which enitity owns the allocation - in our case, the allocations are asked for a KubeVirt VM. Thus, the pod must be templated w/ the required CNI args:

kubectl get pods virt-launcher-vm-rhel8-7fmb7 -ojsonpath="{ @.metadata.annotations.k8s\.v1\.cni\.cncf\.io\/networks }" | jq
[
  {
    "name": "whereabouts-conf",
    "namespace": "default",
    "interface": "pod16367aacb67",
    "cni-args": {
      "whereabouts.cni.cncf.io/ownerID": "8d9d6b85-49e1-4722-9b42-3348d8e9b9f6",
      "whereabouts.cni.cncf.io/ownerName": "vm-rhel8",
      "whereabouts.cni.cncf.io/ownerType": "VirtualMachine",
      "whereabouts.cni.cncf.io/ownerVersion": "kubevirt.io/v1"
    }
  }
]

We are using the OverlappingRangeIPReservation to block the IP allocations (it is its purpose at the end of the day ...) but the "real" proposal will probably add a new CRD for the same function.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer (optional):

[maiqueb]

/cc @oshoval @qinqon

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