Revert "refactor: 清理租户API旧模块代码"

This reverts commit 992930a821.

src/Modules/TakeoutSaaS.Module.Messaging/Serialization/JsonMessageSerializer.cs

@@ -0,0 +1,22 @@
+using System.Text;
+using System.Text.Json;
+
+namespace TakeoutSaaS.Module.Messaging.Serialization;
+
+/// <summary>
+/// 消息 JSON 序列化器。
+/// </summary>
+public sealed class JsonMessageSerializer
+{
+    private static readonly JsonSerializerOptions DefaultOptions = new(JsonSerializerDefaults.Web);
+
+    /// <summary>
+    /// 序列化消息。
+    /// </summary>
+    public byte[] Serialize<T>(T message) => Encoding.UTF8.GetBytes(JsonSerializer.Serialize(message, DefaultOptions));
+
+    /// <summary>
+    /// 反序列化消息。
+    /// </summary>
+    public T? Deserialize<T>(byte[] body) => JsonSerializer.Deserialize<T>(body, DefaultOptions);
+}