Feature: Implement wrapper for ibv_query_rt_values_ex to get real-time hardware values

[atilag]

Hi @dragonJACson !

Feature request: Add wrapper for ibv_query_rt_values_ex to get real-time hardware values

Summary

Implement a safe Rust wrapper for the ibv_query_rt_values_ex function to allow RDMA users to fetch real-time hardware values (such as hardware clock, completion timestamp, etc.) via the Rust API.

Motivation

RDMA applications benefit from accessing real-time values (hardware timestamp, counters, etc.) for performance monitoring and low-latency operations. Currently, the sideway crate has wrappers for many ibverbs core functions, but not for ibv_query_rt_values_ex.
I need to measure some real latencies between peers and I just found out that we would need to implement this verb.
Let me know what you think!
Thanks for sharing this project with the world ❤️ !!

Target

Extend DeviceContext with a new method (e.g. query_rt_values_ex) following the code patterns in the repo.

[atilag]

Oh, a PR is coming, of course!