Add bge-m3 dense, sparse, multi-vector

[yjoonjang]

https://huggingface.co/BAAI/bge-m3

bge-m3 model has 3 versions: dense, sparse, multi_vector.
However, sentence-transformers only allow dense versions, so I think it would be great if mteb makes it available to use other versions.

Can I work on this ?

[Samoed]

Of course! That would be great!

[KennethEnevoldsen]

Probably related to #1211. We currently have no good way to log variations on a model (though I think it is something we should figure out how to do)