* [pipeline/tuning] improve dispatch performance both time and space cost
* [pipeline/converge] add interface for testing convergence
* [NFC] polish colossalai/utils/multi_tensor_apply/multi_tensor_apply.py code style
* Update PipelineBase.py
* [pipeline/chimera] reconstruct PipelineBase and Worker to support more feasible custom schedule | finish Chimera
* [pipeline/chimera] test chimera | fix bug of initializing
* support p2p communication with any type of object | pass test
* reconstruct pipeline schedule with p2p_v2.py(support communication with List[Any]) | pass test
* [engin/schedule] use p2p_v2 to recontruct pipeline_schedule
* [pipeline/rpc] implement a demo for PP with cuda rpc framework
* [pipeline/rpc] support interleaving | fix checkpoint bug | change logic when dispatch data in work_list to ensure steady 1F1B
* [pipeline/rpc] implement distributed optimizer | test with assert_close
* [pipeline/rpc] implement distributed optimizer | test with assert_close
* [pipeline/rpc] update outstanding mechanism | optimize dispatching strategy
* [pipeline/rpc] update outstanding mechanism | optimize dispatching strategy
* [pipeline/rpc] update outstanding mechanism | optimize dispatching strategy
* [pipeline/pipleline_process_group] finish PipelineProcessGroup to manage local abd global rank in TP,DP and PP
* [pipeline/pipleline_process_group] remove comment
* [pipeline/pipleline_process_group] remove comment
* [pipeline/pipleline_process_group] skip process group test
* [pipeline/pipleline_process_group] remove test named function
Hongxin Liu