销量配置日均出单次数，新增取样天数的配置

AutoTurnOver.Models/dc_auto_sales_forecast_config.cs

@@ -53,6 +53,7 @@ namespace AutoTurnOver.Models
         public decimal? first_order_days_max { get; set; }
         public decimal? orders_avg_min { get; set; }
         public decimal? orders_avg_max { get; set; }
+        public int orders_avg_sampling_days { get; set; }
     }
 
     public class dc_auto_sales_forecast_stage_config