core, frontends: callMenu is now async and don't use callback_id anymore

frontends/src/constants.py

@@ -56,6 +56,8 @@ def getPresence():
 class Const(object):
     PRESENCE = getPresence()
 
+    MENU_NORMAL = "NORMAL"
+
     # from plugin_misc_text_syntaxes
     _SYNTAX_XHTML = "XHTML"
     _SYNTAX_CURRENT = "@CURRENT@"