Features
- Extended language support: enable support for languages that rely on [FastText representations](https://fasttext.cc/docs/en/crawl-vectors.html); add support for Hebrew.
- Model support: add Naive Bayes model policies; facilitate adding new transformer-based classifiers.
- Performance improvements for the label import functionality.
- Collecting the set of examples for training now happens in a background thread.
- It is now possible to define _active learning policies_, i.e. a predefined policy for dynamically determining which active learning strategy should be used.
Development
- Initiated migration of the frontend to Typescript (205)