Add article quality pipeline

Adds a article quality pipeline to research-datasets, combinging

• the language agnostic model from https://gitlab.wikimedia.org/repos/research/article-quality, which will be archived after the migration is done. The code has been updated to fit the coding style of the repo, but the logic remains the same
• the standard quality model from the knowledge gaps pipeline https://gitlab.wikimedia.org/repos/research/knowledge-gaps/-/blob/main/knowledge_gaps/feature_metrics.py?ref_type=heads#L44
• support for using the dumps 2.0 wikitext source wmf_dumps.wikitext_raw_rc2
• exposes the model coefficients as pipeline args, e.g. to make it configurable from airflow
• unit tests