backend/sqlstore: move GetDashboardTags to dashboard service (#50091)

+ removing some functions that were already copied to the dashboard service in a previous pr.

pkg/services/sqlstore/datasource.go

@@ -7,13 +7,15 @@ import (
 	"strings"
 	"time"
 
+	"xorm.io/xorm"
+
 	"github.com/grafana/grafana/pkg/components/simplejson"
 	"github.com/grafana/grafana/pkg/events"
 	"github.com/grafana/grafana/pkg/infra/metrics"
 	"github.com/grafana/grafana/pkg/models"
 	ac "github.com/grafana/grafana/pkg/services/accesscontrol"
+	"github.com/grafana/grafana/pkg/util"
 	"github.com/grafana/grafana/pkg/util/errutil"
-	"xorm.io/xorm"
 )
 
 // GetDataSource adds a datasource to the query model by querying by org_id as well as
@@ -287,3 +289,5 @@ func generateNewDatasourceUid(sess *DBSession, orgId int64) (string, error) {
 
 	return "", models.ErrDataSourceFailedGenerateUniqueUid
 }
+
+var generateNewUid func() string = util.GenerateShortUID