Call hsync(), if supported, immediately prior to closing DFS compaction files.

According to [this documentation](https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/filesystem/outputstream.html#HDFS_and_OutputStream.close.28.29) its best to call hsync() prior to close. This could possibly be done for files created for minor and major compaction in Accumulo. For compactions could call StreamCapabilities to see if hsync() is supported and if its then call it immediately before calling close.

Start by locating where minor and major compaction files are created and closed, then read the referenced output-stream documentation and the StreamCapabilities API. Done means each compaction stream checks whether hsync() is supported and calls it immediately before close.

Written by the indexing model from the issue text.