Open API 3.1.0 support

[jefflembeck]

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Closing issues

This addresses number #794.

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Potential Problems With The Approach

There is probably way too much here. I cargo culted a ton of things over from 3.0.0. I also made some changes to how certain types extend others.

Test plan

Broke out tests and fixtures strictly for 3.1. Happy to make changes to that, but wanted something we could start talking out earlier rather than later.

[github-actions]

Hello there jefflembeck 👋

Thank you and congrats 🎉 for opening your first PR on this project.✨

We will review the following PR soon! 👀

[jefflembeck]

My real issue I wanted to get to the bottom of was getting variadic tuples in. But the differences in prefixItems and items and what is possible for 3.1.0 vs 3.0.0 made me shoot for the moon a little.

[bioc-druzgami]

Any news?