Restructure cloudmigration service (#83211)

* Restructure cloudmigation service

* Adjust codewoners and wire

* Comment out unused metrics

pkg/services/cloudmigration/cloudmigrationimpl/metric.go

@@ -0,0 +1,26 @@
+package cloudmigrationimpl
+
+import (
+	"errors"
+
+	"github.com/grafana/grafana/pkg/services/cloudmigration"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// type Metrics struct {
+// 	log log.Logger
+// }
+
+func (s *Service) registerMetrics(prom prometheus.Registerer) error {
+	for _, m := range cloudmigration.PromMetrics {
+		if err := prom.Register(m); err != nil {
+			var alreadyRegisterErr prometheus.AlreadyRegisteredError
+			if errors.As(err, &alreadyRegisterErr) {
+				s.log.Warn("metric already registered", "metric", m)
+				continue
+			}
+			return err
+		}
+	}
+	return nil
+}