fix: implement MyData @DataObject constructor deserialization

Implement the MyData(JsonObject) constructor to deserialize `id` and
`maxSize` fields from the provided JsonObject, replacing the empty TODO.

web-service/src/main/java/cn/qaiu/lz/common/model/MyData.java

@@ -24,6 +24,7 @@ public class MyData implements Serializable {
 
 
     public MyData(JsonObject jsonObject) {
-        // TODO
+        this.id = jsonObject.getString("id");
+        this.maxSize = jsonObject.getString("maxSize");
     }
 }