Explore use of `std::chrono` for time type

[nmm0]

What Needs to be Done?

• What would it take to serialize time points and durations? Are some time points byte-serializable?
• Can we take advantage of high-precision timers?
• Should we use now() from chrono or keep using MPI_Wtime? Is it more/less performant (maybe dependent on implementation)?
• What are the performance implications both in timing operations and serialization?