[SPARK-4483][SQL]Optimization about reduce memory costs during the HashOuterJoin

In `HashOuterJoin.scala`, spark read data from both side of join operation before zip them together. It is a waste for memory. We are trying to read data from only one side, put them into a hashmap, and then generate the `JoinedRow` with data from other side one by one.
Currently, we could only do this optimization for `left outer join` and `right outer join`. For `full outer join`, we will do somthing in another issue.
Can that also be passed in since it will be created per every row in left side? The same in below.