feat(schema): use the type names passed to schema's `types!` macro in type position

[DCNick3]

This gives the IDE a hint that it's a type name and allows one to navigate to the type definition and see name resolution errors

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Checklist

• [x] I've read CONTRIBUTING.md.
• [ ] (optional) I've written unit tests for the code changes.
• [ ] All review comments have been resolved.
• [ ] All CI checks pass.