Add support for exporting Scheduled Events for the VM

[kon-angelo]

Azure provides the capability to query for scheduled events through the medatadata service.

Cloud-provider-Azure already supports a daemon set (the cloud-node-manager) running in the data plane that can be used to query these information. The general idea is that for critical workload, retrieving maintenance events can allow users to react in time and exposing the information through the Node object and/or events can be picked up by existing monitoring infrastructure or be dealt with automated actions based on the node condition.

It would therefore be a great idea for the CNM to support this feature