Use httplib based HTTP client

* Make code work on Windows platform

* Sync with latest PB protocols

* Set access point when querying assignment
* Use third-party thread pool implementation

Support tracing through OpenCensus and transform to OpenTelemetry on exporting

* Fix CMakeLists.txt and bazel 3rd party deps

Add unit tests for log module

Add unit test for ClientImp

Add unit test for PullConsumerImpl

Enhance coverage of the rocketmq module

Improve unit test coverage for client module

Improve unit test coverage for base module

Add session-token when sign with STS access key/secret

Support FIFO and class hierarchy re-structure.