We need a transactional integration testing framework to do some white-box transactional testing. Using this framework, we can easily build a cluster test environment, specify the number of CN, DN, LOG services we need and control the start and stop of these services, and even simulate some network partitioning and error injection

Approved by: @yingfeng, @reusee, @cnutshell, @fengttt

Approved by: @fengttt

memEngine is only for testing in the pkg/sql/compile package, and had been replaced with memoryengine.

Approved by: @fengttt

1. collect stats as column exec_plan_stats
2. record request_at, reponse_at in same table system.statement_info.
    if statement run a long time, there will be two records in table with same value statement_id
3. add ComputationWrapper::RecordExecPlan to collect exec_plan(stats info)
    it will record new format in PR Explain analyze and Support json serialization for UI #5070
4. add pkg/trace codeowner xzxiong

Approved by: @fengttt

Approved by: @fengttt

Approved by: @fengttt

Approved by: @fengttt

Signed-off-by: jinhai <haijin.chn@gmail.com>