Alerting: Scheduler to use AlertRule (#52354)

* update GetAlertRulesForSchedulingQuery to have result AlertRule
* update fetcher utils and registry to support AlertRule
* alertRuleInfo to use alert rule instead of version
* update updateCh hanlder of ruleRoutine to just clean up the state. The updated rule will be provided at the next evaluation
* update evalCh handler of ruleRoutine to use rule from the message and clear state as well as update extra labels

* remove unused function in ruleRoutine
* remove unused model SchedulableAlertRule

* store rule version in ruleRoutine instead of rule
* do not call the sender if nothing to send

pkg/services/ngalert/schedule/fetcher.go

@@ -13,7 +13,7 @@ import (
 // hashUIDs returns a fnv64 hash of the UIDs for all alert rules.
 // The order of the alert rules does not matter as hashUIDs sorts
 // the UIDs in increasing order.
-func hashUIDs(alertRules []*models.SchedulableAlertRule) uint64 {
+func hashUIDs(alertRules []*models.AlertRule) uint64 {
 	h := fnv.New64()
 	for _, uid := range sortedUIDs(alertRules) {
 		// We can ignore err as fnv64 does not return an error
@@ -24,7 +24,7 @@ func hashUIDs(alertRules []*models.SchedulableAlertRule) uint64 {
 }
 
 // sortedUIDs returns a slice of sorted UIDs.
-func sortedUIDs(alertRules []*models.SchedulableAlertRule) []string {
+func sortedUIDs(alertRules []*models.AlertRule) []string {
 	uids := make([]string, 0, len(alertRules))
 	for _, alertRule := range alertRules {
 		uids = append(uids, alertRule.UID)