utf8检查
判断char*是否为utf8编码
https://blog.csdn.net/u010821666/article/details/78233517?utm_medium=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.control&dist_request_id=&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.control