* add logger for remote actors

* resolve issues

* `get_free_tcp_port` and `is_port_available` move to utils.py

* add information for user in the remote log web UI

* yapf formatting

* fix unittest error

* yapf formatting

* update remote job web UI

* add option for log server port

* fix windows support

* fix `os.devnull` in windows

* fix port argument passing

* fix bug

* fix kill log_server

* fix log server not started

* add log_server_test
Co-authored-by: NHongsheng Zeng <zenghongsheng@baidu.com>