Add: the server will be able to add a `_time` field to log row, by specify `log_server_time: bool = True` in LoggerConfig. To use exact client time instead of server time, make your time field when submit a log row.
Refactor: the old design works badly in multiprocessing. Now the framework is migrated to a Client-Server pattern to compatible for multiprocessing usage, such as vLLM.
