Add METEOR score metric for evaluating MT

[sky-2002]

Pull Request Template

Type of Change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Description

This PR intends to add the METEOR metric for evaluating MT tasks. We do have BLEU, which is precision-focused and ROUGE score which focuses on recall, METEOR metric on the other hand fixes some of the problems found in the more popular BLEU and ROUGE metrics and also produce good correlation with human judgment at the sentence or segment level.
Please include a summary of the change and which issue it addresses.
Dependencies - nltk

Checklist

• I have read the CONTRIBUTING document.
• My code follows the code style (BLACK) of this project.
• I have added tests to cover my changes.
• I have updated the documentation accordingly.
• I have added an appropriate CHANGELOG entry.

Author's Note

I have tested my code by only running the test_meteor_operator from the tests/test_operators.py file.