Support Citation File Format (CFF, yaml) as an import format

[Siedlerchr]

JabRef should be able to parse Citation File Format (CFF) and export into it.
Information about the format can be found here.

https://citation-file-format.github.io/
See also https://github.com/citation-file-format/cff-converter-python

Implementation details.
Look at other importers, org.jabref.logic.importer
For YAML parsing, JabRef includes already the jackson yaml parser
https://github.com/FasterXML/jackson-dataformats-text/tree/2.13/yaml

[kno10]

@AidanM11 any progress on a CFF export? I primarily use bibtex, and was looking for an easy bibtex to CFF conversion. Thank you.

[Siedlerchr]

@kno10 So far there is no export. As this issue was about import, I suggest you open a new issue for the Export so we can better tag this

[koppor]

I created #10671 as follow-up. (And also changed title of this closed issue, because the title was misleading: One might think, JabRef supports export of CFF).