Add C++ benchmarks for local IO throughput

[vuule]

Benchmarks should cover different workloads (size/number of reads/writes).
Multi-threaded benchmarks can also be considered.
Is possible, the throughput can be compared to the results from utilities like fio and gdsio.

[GregoryKimball]

@kingcrimsontianyu thanks for completing the first step in #659. What types of benchmarks would be most important to include before we complete the spirit of this issue?

[kingcrimsontianyu]

At minimum, the benchmarks should include the sequential read (write) and random read (write) I/O patterns for KvikIO's FileHandle::pread/pwrite, and report throughput (GiB/s) and IOPS (I/O per second) for these two patterns respectively.

Then we may extend the benchmark to mixed I/O pattern, latency measurement, MmapHandle::pread.