[MD] Add TNER compatibility -> Athena + enable tner env

[hashpad]

https://github.com/asahi417/tner

TNER offers a buuuunch of NER models for HuggingFace, which we can use for mention detection (MD)

Note: They also offer the datasets (yay!)

Rankings: https://github.com/asahi417/tner/blob/master/MODEL_CARD.md