Add translator for CITATION.cff file references (`CFF-References`)

[d33bs]

This PR extends on the work originally provided by @adam3smith for the CFF translator as a new translator called "CFF-References". The purpose of this translator is to help translate Zotero resources into a CITATION.cff file's references item.

Thank you in advance for any thoughts and feedback you may have! Please don't hesitate to let me know if I may change or improve this to help make it more useful to others.

Closes #3250

[d33bs]

I'm uncertain about the best way to proceed with adding tests for a translator. Any guidance would be much appreciated! In case of no reply I'll also reference existing PR's for an idea of how to do this.

[adam3smith]

We don't currently add export tests

[d33bs]

Sounds good, thanks @adam3smith !

[AbeJellinek]

@adam3smith: I think this is ready, but it's always good to get a third set of eyes on import/export translators. Look OK?

[AbeJellinek]

(@d33bs, thanks for adding all those mappings! Sorry again for ballooning the amount of work this translator would need.)

[d33bs]

No worries @AbeJellinek , thank you again for the great feedback - fun to go deeper with this!