Alerting: Add recording rules to ruler API and validation (#87779)

* Read path, main API

* Define record field for incoming requests

* Refactor several alerting specific validators into two paths

* Refactor validateCondition actually contain all the condition validation logic

* Move condition validation inside rule path

* Validators for recording rules

* Wire feature flag through to validators

* Test for accepting a valid recording rule

* Tests for negative case, no UID

* Test for ignoring alerting fields

* Build conditions based on recording rules as well

* Regenerate swagger docs

* Fix CRUD test to cover the right thing

* Re-generate swagger docs with backdated v0.30.2 version

* Regenerate base spec

* Regenerate ngalert specs

* Regenerate top level specs

* Comment and rename

* Return struct instead of modifying ref

pkg/services/ngalert/models/alert_rule.go

@@ -337,6 +337,12 @@ func (alertRule *AlertRule) GetLabels(opts ...LabelOption) map[string]string {
 }
 
 func (alertRule *AlertRule) GetEvalCondition() Condition {
+	if alertRule.IsRecordingRule() {
+		return Condition{
+			Condition: alertRule.Record.From,
+			Data:      alertRule.Data,
+		}
+	}
 	return Condition{
 		Condition: alertRule.Condition,
 		Data:      alertRule.Data,