feature: Added support for populating selects from ajax (#6557)

fixes: #5264

The issue was all the string concatenation...

But I decided to try loading the select via ajax. Seems ok.  We could just use something like select2.  Opinions? Use this approach or load at page load.
I was able to reduce the loading of the 4000 select items from 1.6s to 0.6s on my laptop by optimizing the sql.

I added 4000 devices to my database to check this :)

html/ajax_list.php

@@ -0,0 +1,33 @@
+<?php
+
+/*
+ * LibreNMS
+ *
+ * Copyright (c) 2014 Neil Lathwood <https://github.com/laf/ http://www.lathwood.co.uk/fa>
+ * Copyright (c) 2017 Tony Murray <https://github.com/murrant/>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.  Please see LICENSE.txt at the top level of
+ * the source code distribution for details.
+ */
+
+$init_modules = array('web', 'auth');
+require realpath(__DIR__ . '/..') . '/includes/init.php';
+
+if (!$_SESSION['authenticated']) {
+    echo "Unauthenticated\n";
+    exit;
+}
+
+set_debug($_REQUEST['debug']);
+
+$id = mres($_REQUEST['id']);
+
+if (isset($id)) {
+    if (file_exists("includes/list/$id.inc.php")) {
+        header('Content-type: application/json');
+        include_once "includes/list/$id.inc.php";
+    }
+}