bpo-42990: Refactor _PyFrame_New_NoTrack() (GH-24566)

* Refactor _PyFrame_New_NoTrack() and PyFunction_NewWithQualName()
  code.
* PyFrame_New() checks for _PyEval_BuiltinsFromGlobals() failure.
* Fix a ref leak in _PyEval_BuiltinsFromGlobals() error path.
* Complete PyFunction_GetModule() documentation: it returns a
  borrowed reference and it can return NULL.
* Move _PyEval_BuiltinsFromGlobals() definition to the internal C
  API.
* PyFunction_NewWithQualName() uses _Py_IDENTIFIER() API for the
  "__name__" string to make it compatible with subinterpreters.