csv: Add features

Add the following features:

* Escaping.
* Customization of the CSV format.
* A reader.

Fix #969.

Signed-off-by: Jean-Christophe Beaupré <jcbrinfo@users.noreply.github.com>
un \n après un triple quote est ignoré. tu peux aussi alléger la ligne en éliminant les pathentheses

~~~
var example = new StringIStream """
foo,bar\r
"Hello, word!",1234.5 + 42\r
"Something\r
""else""\", baz\r
"""
~~~