Azure RedHat Openshift (ARO) support

[jbianquetti-nami]

Add support for ARO in cloud custodian

Example policy:

policies:
  - name: broken-open-shift
    resource: azure.open-shift
    filters:
      - type: value
        key: name
        op: equal
        value_type: normalize
        value: environment-64ozd
    actions:
      - type: delete

[jbianquetti-nami]

@kapilt Would you take a look at this? Thanks.

[kapilt]

ci seems to be failing on docs due to /home/runner/work/cloud-custodian/cloud-custodian/docs/source/azure/resources/aro.rst: WARNING: document isn't included in any toctree

I do wonder if thats an artifact of caching in the docs ci independent of this pr.

[kapilt]

thanks, lgtm