Move metricbeat azure module to GA

[narph]

• Ensure the requirements are met.
• Move the module to GA

TO DO:

• Automated checks that all fields are documented
• Fields follow ECS and naming conventions
• Example data.json exists and an automated way to generate it exists (go test -data)
• Map resource size to event (in case of compute_vm and compute_vm_scaleset), would require additional api calls (optional)

[narph]

cc: @sorantis