move wxKEY_XXX constants to wx/defs.h from wx/list.h and wx/hash.h to avoid duplicating their declarations

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45652 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/defs.h

@@ -1695,6 +1695,16 @@ enum wxBackgroundStyle
   wxBG_STYLE_CUSTOM
 };
 
+/*
+ * Key types used by (old style) lists and hashes.
+ */
+enum wxKeyType
+{
+    wxKEY_NONE,
+    wxKEY_INTEGER,
+    wxKEY_STRING
+};
+
 /*  ---------------------------------------------------------------------------- */
 /*  standard IDs */
 /*  ---------------------------------------------------------------------------- */