Sort shuffle read improvements

Hi @sryza , I've done some improvements in current SortSHuffleRead, would you mind help reviewing this and give me some comments, thanks a lot!

1. copy memory shuffle block from off-heap to on-heap if memory is allocated with direct memory to control the off-heap memory size.
2. Some code style modification and better failure processing logic.
From my side I think it's ready to submit, I'm not sure is there anything we forget to do. Though we can still improve it according to my test, I think we can do this step by step.