21 support for different metrics

[BenediktStuhrmann]

What does this PR do?

Added functionality for mapping datasets to a universal/generic representation (per skill-type). Currently supports extractive-qa and multiple-choice-qa. Added functionality for mapping predictions to metric-format. Added functionality for mapping references (in universal dataset-format) to metric-format. Integrated mapping of dataset and mapping for metrics into predict and evaluate endpoints.

For testing: Extractive-QA Skill: 62c1ae1b536b1bb18ff91ce3 Mocked dataset-metadatas: squadand quoref

Multiple-Choice Skill: 62c1ae19536b1bb18ff91cde Mocked dataset-metadata: commonsense_qa and cosmos_qa

Currently supported metrics: exact_match, squad, squad_v2

Before submitting / marking as 'ready to review'

• [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• [ ] Did you make sure to update the documentation with your changes?
• [ ] Did you write any new necessary tests?

[nclskfm]

Hast noch 1 merge conflict @BenediktStuhrmann

[BenediktStuhrmann]

Hast noch 1 merge conflict @BenediktStuhrmann

Fixed