Move the extracting join keys logic to optimizer #4710
Description
Is your feature request related to a problem or challenge? Please describe what you are trying to do.
Currently the extract_join_keys is only invoked in the sql planner(join), then the join api of dataframe needs explictly specify the equijoin predicate if they want equijoin.
Describe the solution you'd like
I would like to move the extract_join_keys to optimizer.
Describe alternatives you've considered
Additional context