Restructure cloudmigration service (#83211)

* Restructure cloudmigation service

* Adjust codewoners and wire

* Comment out unused metrics

pkg/services/cloudmigration/cloudmigrationimpl/xorm_store.go

@@ -0,0 +1,16 @@
+package cloudmigrationimpl
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/infra/db"
+	"github.com/grafana/grafana/pkg/services/cloudmigration"
+)
+
+type sqlStore struct {
+	db db.DB
+}
+
+func (ss *sqlStore) MigrateDatasources(ctx context.Context, request *cloudmigration.MigrateDatasourcesRequest) (*cloudmigration.MigrateDatasourcesResponse, error) {
+	return nil, cloudmigration.ErrInternalNotImplementedError
+}