Alerting: Implement setting of version message in convert API. (#114331)

Part 2 of adding version messages to the `alert_rule_version` able. This allows
setting the message via a header when using the Prometheus conversion API,
which can be useful for e.g. linking changes back to source control.

pkg/storage/unified/federated/stats_test.go

@@ -79,8 +79,8 @@ func TestIntegrationDirectSQLStats(t *testing.T) {
 
 	ruleStore := ngalertstore.SetupStoreForTesting(t, db)
 	dashboardUID := "test"
-	_, err = ruleStore.InsertAlertRules(context.Background(), ngmodels.NewUserUID(tempUser), []ngmodels.AlertRule{
-		{
+	_, err = ruleStore.InsertAlertRules(context.Background(), ngmodels.NewUserUID(tempUser), []ngmodels.InsertRule{{
+		AlertRule: ngmodels.AlertRule{
 			DashboardUID: &dashboardUID,
 			UID:          "test",
 			Title:        "test",
@@ -102,7 +102,7 @@ func TestIntegrationDirectSQLStats(t *testing.T) {
 			ExecErrState:    ngmodels.ExecutionErrorState(ngmodels.Alerting),
 			NoDataState:     ngmodels.Alerting,
 			IntervalSeconds: 60,
-		}})
+		}}})
 	require.NoError(t, err)
 
 	_, err = dashStore.SaveDashboard(ctx, dashboards.SaveDashboardCommand{