[ims] Define ClusterRequest CRD and create o2ims controller managing its lifecycle

[adetalhouet]

See design details here: https://docs.google.com/presentation/d/1iyE_XLkBJkl_ClYsE_vRnEkm8Ica7YE0/edit#slide=id.p1

In scope:

• creation of the API and the initial controller reconciling it. Here is an example CR.

  • the clusterTempalteRef should point to an existing PackageVariant

    apiVerson: o2ims.provisioning.oran.org/v1alpha1
    kind: ClusterRequest
    metadata:
    name: Cluster1
    namespace: default
    spec:
    clusterTemplateRef: O-CloudClusterTemplate1
    siteRef: Site-1

• controller should use the clusterTemplateRef field to identify the PackageVariant to deploy

• controller should use the siteRef to identify the target site where the cluster should be deployed.

  • Use the WorkloadCluster CRs, along with the nephio.org/region label
  • If a cluster already exist in that site, nothing should be done. The details of the cluster will be provided through the status of the CR, handled here https://github.com/nephio-project/nephio/issues/758
  • if no cluster exists at that site, deploy the PackageVariant

Out of scope:

• Status monitoring and reporting