support custom resource

[Iceber]

When collecting custom resources, you need to specify the version to be synchronized.
eg.

    resources:
    - group: apps
      resources:
      - deployments
    - group: cert-manager.io
      resources:
      - issuers
      versions:
      - v1
      - v1beta1
      - v1alpha2

If no version is specified, then the top three versions of the priority order in the member cluster will be synchronized by default.

  status:
    resources:
    - group: cert-manager.io
      resources:
      - kind: Issuer
        namespaced: true
        resource: issuers
        syncConditions:
        - lastTransitionTime: "2021-12-07T02:14:21Z"
          status: Syncing
          storageVersion: v1
          version: v1
        - lastTransitionTime: "2021-12-07T03:57:08Z"
          status: Syncing
          storageVersion: v1beta1
          version: v1beta1
        - lastTransitionTime: "2021-12-07T03:57:08Z"
          status: Syncing
          storageVersion: v1alpha3
          version: v1alpha3

[Iceber]

Since different versions may exist in different clusters, and the conversion strategy between these versions may also be Webhook, redundant data is saved if multiple versions are synchronized.

In the next stage, the versions of custom resources in different clusters are reconciled in the clustersynchro manager by watching for the CRD resources.

If there is an intersection between the versions of custom resources between clusters and the conversion strategy is None, then only one version needs to be synchronized in the cluster and saved as the same version.

if the conversion strategy for a custom resource between clusters is Webhook, then it falls back to the default synchronization policy