Add PyType_GetBaseByToken function with Py_tp_token slot

[neonene]

This issue implements a proposal related to PEP-489 and PEP-630.

Decision:

• Add Py_tp_token slot and PyType_GetBaseByToken function capi-workgroup/decisions#34

TODO:

• Implement the feature
• Use it in _PyStgInfo_FromType_NoState() in _ctypes.c

TODO (optional):

• Replace PyType_GetModuleByDef() in defdict_or() (_collectionsmodule.c)
• Replace _PyType_GetModuleByDef2() in _decimal.c
• Remove _PyType_GetModuleByDef2()

Has this already been discussed elsewhere?

I have already discussed this feature proposal on Discourse

Links to previous discussion of this feature:

• Better support for type checking encukou/abi3#19
• https://discuss.python.org/t/55598

Linked PRs

• gh-124153: Introduce PyType_GetBaseByToken function (PoC) #121079
• gh-124153: Implement PyType_GetBaseByToken() and Py_tp_token slot #124163

[encukou]

The first PR is merged. Keeping this open for the other TODO items.