libraryelements: Spanner compability (#103881)

* libraryelements: fix compatibility with Spanner

* Log errors leading to status code 500.

* Rename tests to make them integration tests.

pkg/services/libraryelements/libraryelements_delete_test.go

@@ -4,15 +4,16 @@ import (
 	"encoding/json"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/grafana/grafana/pkg/components/simplejson"
 	"github.com/grafana/grafana/pkg/services/dashboards"
 	"github.com/grafana/grafana/pkg/services/libraryelements/model"
 	"github.com/grafana/grafana/pkg/services/org"
 	"github.com/grafana/grafana/pkg/web"
-	"github.com/stretchr/testify/require"
 )
 
-func TestDeleteLibraryElement(t *testing.T) {
+func TestIntegration_DeleteLibraryElement(t *testing.T) {
 	scenarioWithPanel(t, "When an admin tries to delete a library panel that does not exist, it should fail",
 		func(t *testing.T, sc scenarioContext) {
 			resp := sc.service.deleteHandler(sc.reqContext)