Make metrics and alerts compatible with KubeVirt observability best practices

[tiraboschi]

metrics

• the naming needs to follow the format kubevirt_$operator_$metricName, so for example, virt_platform_compliance_status should become something like kubevirt_autopilot_compliance_status
• onboard the linter: https://github.com/kubevirt/monitoring/tree/main/test/metrics/prom-metrics-linter

alerts

• move runbooks to https://github.com/kubevirt/monitoring/tree/main/docs/runbooks
• add additional labels on the alerts for better management, we should use also:
  • kubernetes_operator_part_of: kubevirt
  • kubernetes_operator_component: autopilot (can replace your current operator label)
  • operator_health_impact: (same range of values as severity)