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.
Not sure how much of a difference it makes (probably little), but I'd add the full URL only for those items that are actually selected, i.e. before pushing this to articles in line 51.