bpo-40137: Add pycore_moduleobject.h internal header (GH-25507)

Add pycore_moduleobject.h internal header file with static inline
functions to access module members:

* _PyModule_GetDict()
* _PyModule_GetDef()
* _PyModule_GetState()

These functions don't check at runtime if their argument has a valid
type and can be inlined even if Python is not built with LTO.

_PyType_GetModuleByDef() uses _PyModule_GetDef().

Replace PyModule_GetState() with _PyModule_GetState() in the
extension modules, considered as performance sensitive:

* _abc
* _functools
* _operator
* _pickle
* _queue
* _random
* _sre
* _struct
* _thread
* _winapi
* array
* posix

The following extensions are now built with the Py_BUILD_CORE_MODULE
macro defined, to be able to use the internal pycore_moduleobject.h
header: _abc, array, _operator, _queue, _sre, _struct.
diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index 99be69c..cae49a0 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -67,6 +67,7 @@
 /* ---------------------------------------------------------------*/
 
 #include "Python.h"
+#include "pycore_moduleobject.h"  // _PyModule_GetState()
 #ifdef HAVE_PROCESS_H
 #  include <process.h>            // getpid()
 #endif
@@ -86,7 +87,7 @@ typedef struct {
 static inline _randomstate*
 get_random_state(PyObject *module)
 {
-    void *state = PyModule_GetState(module);
+    void *state = _PyModule_GetState(module);
     assert(state != NULL);
     return (_randomstate *)state;
 }
@@ -538,7 +539,7 @@ random_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 
     if (PyTuple_GET_SIZE(args) == 1)
         arg = PyTuple_GET_ITEM(args, 0);
-    
+
     tmp = random_seed(self, arg);
     if (tmp == NULL) {
         Py_DECREF(self);