* [Alerting]: Fix empty rules evaluation statuses
`GetRuleGroupAlertRules()` requires an non empty namespaceUID
* Include the namespace into the response
q:="SELECT DISTINCT rule_group FROM alert_rule WHERE org_id = ?"
varruleGroups[][]string
q:="SELECT DISTINCT rule_group, namespace_uid, (select title from dashboard where org_id = alert_rule.org_id and uid = alert_rule.namespace_uid) FROM alert_rule WHERE org_id = ?"