library settings: allow extra

[antoinejeannot]

Hi 👋

This PR's only aim is to allow extra fields as part of LibrarySettings.

This feature comes from the fact that we should be able to store custom settings when instantiating a ModelLibrary with a LibrarySettings.

A few use-cases I have come across:

• sharing an aiohttp ClientSession to all async models of my ModelLibrary, as recommended by the reference
• sharing the main thread event loop
• TL;DR: sharing settings instantiated and set up at startup time

Looking forward to your feedback

[ldeflandre]

simple and efficient.

In the future, we could support all this async session and event loop sharing more explicitly so we can fix the unconsistent behaviors of Async models.

What do you think ?

[antoinejeannot]

Async can get very tricky when using modelkit, as experienced by our current initiatives.

It's certain that there is some room for improvements, I will definitely give it a shot in a few :)

Thanks!