Move DurationInfo from hadoop-aws to hadoop-common org.apache.hadoop.util

It'd be useful to have DurationInfo usable in other places (e.g. distcp, abfs, ...). But as it is in hadoop-aws under {{org.apache.hadoop.fs.s3a.commit.DurationInfo
org.apache.hadoop.fs.s3a.commit.DurationInfo}} we can't do that

Move it.

We'll have to rename the Duration class in the process, as java 8 time has a class of that name too. Maybe "OperationDuration", with DurationInfo a subclass of that

Probably need a test too, won't it?