REQ-3345: 保存群业务扩展字段

im-center-server/src/main/java/cn/axzo/im/entity/Group.java

@@ -29,6 +29,7 @@ public class Group {
     private String name;
     private String bizCode;
     private GroupType type;
+    @TableField(typeHandler = FastjsonTypeHandler.class)
     private Map<String, Object> bizGroupInfo;
     private String avatar;
     private Long memberCount;