DAOS-17644 gurt: Add server object I/O latency histogram

[wangdi1]

Add server I/O latency histogram, and add %50 90% 99% latency to metrics.

Steps for the author:

• [ ] Commit message follows the guidelines.
• [ ] Appropriate Features or Test-tag pragmas were used.
• [ ] Appropriate Functional Test Stages were run.
• [ ] At least two positive code reviews including at least one code owner from each category referenced in the PR.
• [ ] Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• [ ] Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions[bot]]

Ticket title is 'Add server object I/O latency histogram' Status is 'Open' https://daosio.atlassian.net/browse/DAOS-17644