mobile ui: implement dummy message box and scrip loader

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

www/mobile/Toolkit.js

@@ -6,3 +6,10 @@ Ext.Ajax.setDisableCaching(false);
 
 // do not send '_dc' parameter
 Ext.Ajax.disableCaching = false;
+
+Ext.MessageBox = Ext.Msg = {
+    alert: (title, message) => console.warn(title, message),
+    show: ({title, message}) => console.warn(title, message),
+};
+
+Ext.Loader.injectScriptElement = (url) => console.warn(`surpressed loading ${url}`)