Improve hive compatibility with TIMESTAMP partition column.

Currently, Tajo allow to use TIMESTAMP column as a partition key. But if users use TIMESTAMP partition column, Tajo doesn't keep the original TIMESTAMP values. Actually, Tajo automatically converts TIMESTAMP values to STRING literals which are accepted in the format YYYY-MM-DD HH:MM:SS. As a result, Tajo can't keep mills of second and can't provide right hive compatibility

We need to support hive compatibility for all partition column types. But when using TIMESTAMP partition column, users might not get correct partitions occasionally because tajo partition name is different from hive partition name. Actually, Tajo automatically converts TIMESTAMP values to STRING literals which are accepted in the format YYYY-MM-DD HH:MM:SS. But Hive automatically converts it to STRING literals which are accepted in the format YYYY-MM-DD HH:MM:SS.MS.