* streaming writer use event driven model.
* add RefreshChannelInfo
* fix name
* minor changes according reviewer comments
* Fix according to reviewer's comments
* fix bazel lint
* code polished
* Add more comments
* rename Stop & Start of EventQueue to Freeze and Unfreeze.
* add override
* fix
* fix return value
* support flow control
* add flow control ut in mock transfer
* minor changes according to comments
* add java and python worker adaption
Co-authored-by: wanxing <wanxing.wwx@alibaba-inc.com>
