Systematically distinguish accumulated parallel time from walltime

[yibin87]

Enhancement

Currently, the "time" field in execution info may represent the execution time of a specific executor or the total execution time of multiple "cloned" executors which are executed parallely, such as ParallelApply cases：

This situation is very confusing, since the Limit_17 operator's time is much more than its parent operator's time. So it is necessary to distinguish between these two meanings. At the same time, it is best to have a systematic and unified method to avoid processing each operator independently.