Add functions to configure the Python initialization (:pep:`741`):
* :c:func:`PyInitConfig_Create`
* :c:func:`PyInitConfig_Free`
* :c:func:`PyInitConfig_GetError`
* :c:func:`PyInitConfig_GetExitCode`
* :c:func:`PyInitConfig_HasOption`
* :c:func:`PyInitConfig_GetInt`
* :c:func:`PyInitConfig_GetStr`
* :c:func:`PyInitConfig_GetStrList`
* :c:func:`PyInitConfig_FreeStrList`
* :c:func:`PyInitConfig_SetInt`
* :c:func:`PyInitConfig_SetStr`
* :c:func:`PyInitConfig_SetStrList`
* :c:func:`PyInitConfig_AddModule`
* :c:func:`Py_InitializeFromInitConfig`
Patch by Victor Stinner.