Add support for FinMTEB benchmark

[alt-glitch]

Checklist

• Run tests locally to make sure nothing is broken using make test.
• Run the formatter to format the code using make lint.

Adding datasets checklist

Reason for dataset addition: (FinMTEB Benchmark and Dataset:

• Discussion: Add FinMTEB #1267

• I have run the following models on the task (adding the results to the pr). These can be run using the mteb -m {model_name} -t {task_name} command.

  • sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2
    • Ran only on FiQAClassification as of now.
  • intfloat/multilingual-e5-small
    • Ran only on FINAL as of now.

• I have checked that the performance is neither trivial (both models gain close to perfect scores) nor random (both models gain close to random scores).

• If the dataset is too big (e.g. >2048 examples), considering using self.stratified_subsampling() under dataset_transform()

• I have filled out the metadata object in the dataset file (find documentation on it here).

• Run tests locally to make sure nothing is broken using make test.

• Run the formatter to format the code using make lint.

[alt-glitch]

Hey @Muennighoff @KennethEnevoldsen @isaac-chung!

Here's a WIP PR to close #1267.

I had a few questions/notes:

1. Should I run and get the results for all the tasks?
2. Should the relevant PRs to embeddings-benchmark/results and embeddings-benchmark/leaderboard be made after merging this PR?
3. FiQA2018 is already in MTEB, so I have left that out from FinMTEB. Otherwise, there were no conflicting tasks.
4. Some tasks don't have a reference URL.
5. The Summarization tasks are still pending. I have yet to look into the changes highlighted by @yixuantt in Add FinMTEB #1267 for summarization.

I'll add the summarization changes and make the PRs to results and leaderboard once this is done.
Is there anything else I'm missing out on?

[isaac-chung]

Hi @alt-glitch , thanks for working on this!

1. Yes, I'd suggest running the whole thing on a small model mentioned in the paper like all-MiniLM-L12-v2, and only using the quickest settings as a sanity check, e.g. n_experiments=1 for classification.
2. Afterwards for the leaderboard yes. I'll leave the results repo part to @KennethEnevoldsen
3. Sounds good.
4. I think it's ok to use the paper's URL or its GitHub URL as reference. Otherwise, there are individual references for each dataset mentioned in the paper.
5. Re: summarization task, we can add column names as a class attributes to AbstaskSummarization like the way we did in MIEB's AbsTaskImageClassification.

Let me know if anything is unclear.

[KennethEnevoldsen]

Re. 2: PRs to embeddings-benchmark/results can be made after this PR. I don't believe a PR to embeddings-benchmark/leaderboard will be required once the new leaderboard is up and running as long as the benchmark is added to it is added to benchmarks.py