Map cloud.instance.id to the vm id in the compute_vm metricset

[narph]

Resulted from #19758.

We are currently matching cloud.instance.id to the azure resource id in all azure metricsets.
This does not necessary match the definition of this property and also it's implementation in the add_cloud_metadata processor.

Few steps here to match the vm id to the cloud.instance.id:

• remove the matching of the cloud.instance.id for all metricsets as they don't comply
• add the azure.resource.id property back to all metricsets
• the mapping of fields implementation is shared by all metricsets so the best course of action in this case is to:
  • rewrite compute_vm as a light metricset (will not affect event format/config)
  • add a processor for mapping the machine size, instance id and any future cloud related fields we will add at this level

PR in progress.

[elasticmachine]

Pinging @elastic/integrations-platforms (Team:Platforms)