Add FFI definitions for PEP 573 functions

[messense]

1. PEP 573: https://peps.python.org/pep-0573/#summary-of-api-changes-and-additions
2. https://bugs.python.org/issue42171
3. PyType_FromModuleAndSpec: https://docs.python.org/3/c-api/type.html#c.PyType_FromModuleAndSpec
4. PyType_GetModule: https://docs.python.org/3/c-api/type.html#c.PyType_GetModule
5. PyType_GetModuleState: https://docs.python.org/3/c-api/type.html#c.PyType_GetModuleState
6. PyModule_AddType: https://docs.python.org/3/c-api/module.html#c.PyModule_AddType

[davidhewitt]

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