[Alerting]: Extend quota service to optionally set limits on alerts (#33283)

* Quota: Extend service to set limit on alerts

* Add test for applying quota to alert rules

* Apply suggestions from code review

Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

* Get used alert quota only if naglert is enabled

* Set alert limit to zero if nglalert is not enabled
Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

pkg/models/quotas.go

@@ -44,33 +44,38 @@ type GlobalQuotaDTO struct {
 }
 
 type GetOrgQuotaByTargetQuery struct {
-	Target  string
-	OrgId   int64
-	Default int64
-	Result  *OrgQuotaDTO
+	Target           string
+	OrgId            int64
+	Default          int64
+	IsNgAlertEnabled bool
+	Result           *OrgQuotaDTO
 }
 
 type GetOrgQuotasQuery struct {
-	OrgId  int64
-	Result []*OrgQuotaDTO
+	OrgId            int64
+	IsNgAlertEnabled bool
+	Result           []*OrgQuotaDTO
 }
 
 type GetUserQuotaByTargetQuery struct {
-	Target  string
-	UserId  int64
-	Default int64
-	Result  *UserQuotaDTO
+	Target           string
+	UserId           int64
+	Default          int64
+	IsNgAlertEnabled bool
+	Result           *UserQuotaDTO
 }
 
 type GetUserQuotasQuery struct {
-	UserId int64
-	Result []*UserQuotaDTO
+	UserId           int64
+	IsNgAlertEnabled bool
+	Result           []*UserQuotaDTO
 }
 
 type GetGlobalQuotaByTargetQuery struct {
-	Target  string
-	Default int64
-	Result  *GlobalQuotaDTO
+	Target           string
+	Default          int64
+	IsNgAlertEnabled bool
+	Result           *GlobalQuotaDTO
 }
 
 type UpdateOrgQuotaCmd struct {