Automatic merge from submit-queue (batch tested with PRs 55594, 47849, 54692, 55478, 54133). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Added service annotation to set Azure DNS label for public IP

**What this PR does / why we need it**: Added a feature to set the DNS label for public IPs in the Azure cloud.
For example:
```
apiVersion: v1
kind: Service
metadata:
  annotations:
    service.alpha.kubernetes.io/label-name: myservice
...
```
Will resolve myservice.westus.cloudapp.azure.com to the service's IP.

**Which issue this PR fixes**: fixes #44775

**Special notes for your reviewer**: Note that this is defining a new annotation, so feel free to point out if there is a preferred convention or anything else that needs to be done.

**Release note**:
```release-note
New service annotation "service.beta.kubernetes.io/azure-dns-label-name" to set Azure DNS label name for public IP
```