Merge: CSV Benchmarks

This PR introduces a new benchmark script for CSV parsers.

Are tested here:

* Nit CSV Ad-hoc parser
* Go standard parser
* Java Apache Commons CSV parser
* Python - Pandas
* Python - Standard
* Ruby - Standard

Will upload some measurements later but *spoiler alert* Python - Pandas is the fastest on large files, Ruby is the slowest by far, Java is the second slower with a big margin from the rest.
Go/Nit/Python-Standard are almost equivalent.

Pull-Request: #2072
Reviewed-by: Jean Privat <jean@pryen.org>