Switch to Criterion for Benchmarking.

[sfleischman105]

Right now, we use the standard libraries benchmarking tool for benchmarking.

Despite it's easy of use, there are a couple drawbacks for using it:

• No customization on the number of runs
• Output is limited to a number + estimated degree of confidence

It would be beneficial to switch the benchmarks to Criterion.rs, to get more detailed analysis of the benchmarks, alongside additional benchmark customization.

[sfleischman105]

May I note, this is especially important as it gives the ability to benchmark with a setup stage in-between runs, ala Bencher::iter_with_setup.

[sfleischman105]

Closed with #95