C API: Add `Py_GetBuildInType` and `Py_GetBuildInTypeBorrowed`

[bschoenmaeckers]

Feature or enhancement

Proposal:

Currently, the C API exports all build-in types as a static data export. This limits how alternative python implementations can implement static types.

I propose that we export a Py_GetBuildInTypeBorrowed function that works similar to the Py_GetConstantBorrowed function. And use these in the type check macro's when compiling for the limited api.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

[picnixz]

This needs a DPO discussion. Please open one at discuss.python.org either under the ideas section or core development (and possibly involves the C API working group)