AlertingNG: remove warn/crit from eval prototype (#28334)

and misc cleanup

pkg/api/dtos/ngalert.go

@@ -6,7 +6,7 @@ import (
 	eval "github.com/grafana/grafana/pkg/services/ngalert"
 )
 
-type EvalAlertConditionsCommand struct {
-	Conditions eval.Conditions `json:"conditions"`
-	Now        time.Time       `json:"now"`
+type EvalAlertConditionCommand struct {
+	Condition eval.Condition `json:"condition"`
+	Now       time.Time      `json:"now"`
 }