✨ Support for Pydantic models

[kdeyev]

Brief support for #111.

• the plain Pydantic models are handled the same way as Tuples.
• more complicated Pydantic models are handles as FileText.

The implementation definitely can be improved.
Please let me know what do you think.

[github-actions]

This pull request has a merge conflict that needs to be resolved.

[tiangolo]

Thanks for the interest here! ☕

There's a bunch of refactors we'll need to do first which will affect this, e.g. create conflicts, alter the design, etc. So it will be better to start again later at the right time.

I have been avoiding closing PRs before I have an alternative to provide, but then I've left them open for too long, sorry for that.

For now, I'll close this one for cleanup. But we'll continue tracking this internally to work on it again once what's needed underneath is ready. Thanks! 🍰