A new entry in here that uses wbgetnetities/Special:EntityData instead of the native core API module for RevDocById

Code: https://github.com/wikimedia/revscoring/blob/master/revscoring/extractors/api/datasources.py

And use it in https://github.com/wikimedia/revscoring/blob/5093fc1281a28f8be72d58baee1b719ea0bb8ce2/revscoring/extractors/api/extractor.py