Breakdown reported times

[jeanbez]

• [ ] Add observed I/O time
• [ ] Add observed I/O rate
• [ ] Rename observed time to benchmark walltime/runtime
• [ ] Rename observed rate to benchmark rate
• [ ] Rename raw time to raw I/O time
• [ ] Rename raw rate to raw I/O rate
• [ ] Group metadata, raw I/O together, and improve overall groupping
• [ ] Ensure both CSV and output have these changes

[sbyna]

Rename observed rate to benchmark rate --> this is not needed.