Enable FSM compilation message toggle

[cpfiffer]

This message pops up quite a bit, especially when you have a variety of schemas to generate.

https://github.com/outlines-dev/outlines/blob/8e94488d4ee3c5a29a919d0b9e19f7ea4170b1f4/outlines/fsm/regex.py#L805

It'd be nice to be able to have the option to disable it. What would be a good approach? Keyword arguments?

[rlouf]

I guess that's the standard way of doing it.