Parallel execution of CLIs

[kdeldycke]

To speed up mpm, we can try to have all sub-CLIs executed in a thread pool or a bunch of sub-proccesses.

See:

• https://www.integralist.co.uk/posts/python-asyncio/
• https://leimao.github.io/blog/Python-tqdm-Multiprocessing/
• https://superfastpython.com/python-concurrency-choose-api/
• https://textual.textualize.io/blog/2023/03/08/overhead-of-python-asyncio-tasks/
• https://tenthousandmeters.com/blog/python-behind-the-scenes-12-how-asyncawait-works-in-python/