Promote Node Zone/Region Topology Labels to GA

[andrewsykim]

What type of PR is this?
/kind api-change

What this PR does / why we need it:
Updates the following labels:

failure-domain.beta.kubernetes.io/zone -> topology.kubernetes.io/zone
failure-domain.beta.kubernetes.io/region -> topology.kubernetes.io/region

These are widely used labels and although there's a bit of work involved in renaming them, we should update the label names to reflect general availability of these labels. This PR updates settings of the zone/region labels to apply both the beta and GA labels. We will be supporting both labels for the next few releases and eventually phase out the use of beta labels entirely in favor of the GA ones.

Concretely this PR:

• adds the new GA labels
• update node controller to apply both GA and beta labels for new and existing nodes (out-of-tree node registration)
• update kubelet to apply both GA and beta labels for new and existing (in-tree node registration)
• updates scheduler to read both labels when determining zone predicates (but only the first label found is used)

Which issue(s) this PR fixes:
KEP: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cloud-provider/20190215-promoting-cloud-provider-labels.md

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Deprecate the beta labels for zones ("failure-domain.beta.kubernetes.io/zone") and 
regions ("failure-domain.beta.kubernetes.io/region") in favor of their GA equivalents:
"topology.kubernetes.io/zone" and "topology.kubernetes.io/region". 

The beta labels "failure-domain.beta.kubernetes.io/zone" and "failure-domain.beta.kubernetes.io/region" will be removed in v1.21

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[andrewsykim]

/assign @thockin @msau42 @bsalamat

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andrewsykim, liggitt

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Needs approval from an approver in each of these files:

• pkg/OWNERS [liggitt]
• plugin/pkg/admission/noderestriction/OWNERS [liggitt]
• staging/src/k8s.io/api/OWNERS [liggitt]
• staging/src/k8s.io/cloud-provider/OWNERS [andrewsykim,liggitt]
• test/e2e/framework/OWNERS [andrewsykim,liggitt]

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[andrewsykim]

Revert commits squashed

[liggitt]

/lgtm