调整数据库结构，实现消息模板管理

Atomx.Common/Entities/Currency.cs

@@ -6,6 +6,7 @@ namespace Atomx.Common.Entities
     /// <summary>
     /// 货币信息
     /// </summary>
+    [Table("Currencies")]
     public class Currency
     {
         /// <summary>
@@ -15,6 +16,11 @@ namespace Atomx.Common.Entities
         [Key]
         public int Id { get; set; }
 
+        /// <summary>
+        /// 站点ID
+        /// </summary>
+        public long SiteId { get; set; }
+
         /// <summary>
         /// 货币名称，系统
         /// </summary>