py39: Automatically call resize_term(0, 0) for get{ch,key,_wch}()

Hand-hacked the patch file from a previous commit to get these results
roughly like so:

1. git format-patch -1 30ca08b
2. $EDITOR $OUTPUT.patch
3. (remove all the changes except the py38 ones)
4. s/py38/py39/g
5. git am $OUTPUT.patch

Built and tested against Python 3.9rc1 on Windows 10 using
Microsoft (R) C/C++ Optimizing Compiler Version 19.27.29111 for x64.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>

py39/_cursesmodule.c

@@ -1280,6 +1280,12 @@ _curses_window_getch_impl(PyCursesWindowObject *self, int group_right_1,
     else {
         rtn = mvwgetch(self->win, y, x);
     }
+
+    // windows-curses hack to make resizing work the same as in ncurses.  See
+    // PDCurses' documentation for resize_term().
+    if (rtn == KEY_RESIZE)
+        resize_term(0, 0);
+
     Py_END_ALLOW_THREADS
 
     return rtn;
@@ -1317,6 +1323,12 @@ _curses_window_getkey_impl(PyCursesWindowObject *self, int group_right_1,
     else {
         rtn = mvwgetch(self->win, y, x);
     }
+
+    // windows-curses hack to make resizing work the same as in ncurses.  See
+    // PDCurses' documentation for resize_term().
+    if (rtn == KEY_RESIZE)
+        resize_term(0, 0);
+
     Py_END_ALLOW_THREADS
 
     if (rtn == ERR) {
@@ -1384,8 +1396,14 @@ _curses_window_get_wch_impl(PyCursesWindowObject *self, int group_right_1,
         PyErr_SetString(PyCursesError, "no input");
         return NULL;
     }
-    if (ct == KEY_CODE_YES)
+    if (ct == KEY_CODE_YES) {
+        // windows-curses hack to make resizing work the same as in ncurses.  See
+        // PDCurses' documentation for resize_term().
+        if (rtn == KEY_RESIZE)
+            resize_term(0, 0);
+
         return PyLong_FromLong(rtn);
+    }
     else
         return PyUnicode_FromOrdinal(rtn);
 }