Adding a translator for french union catalog CCFr

As requested in [Zotero Forum](https://forums.zotero.org/discussion/37503) I've built this first version of a translator. 

It still misses somes specific cases but works for > 90% of records I'd say. CCFr catalog is full of JS, not that easy to parse.

Tests are style missing, hope it's not blocking.
So this actually never happens. (because of `default` in `switch`). Remove to avoid confusion.