Rewrite ISIS Adjacency discovery/polling (#13155)

* Rewrite ISIS Adjacency discovery/polling
hopefully much faster now, do most work in discovery and just check up/down in poller.

* unused variable

* Implement option for OS override

* fix an incorrect typehint

* test data

* work around stupid migration name

* update schema

* better handling for the on-demand discovery

* more detailed phpdoc

* fix when adjacency is not found

* don't clear out data when adjacency goes away

* Adjust nullable fields

* fixes

* fix class name

* correct migration

* fix bug causing adjacency data to always be blank

* port popups for port links

* isisISAdjState does not need to be nullable

* remove extra space

* default off

* If port is missing return $text

* update schema

* Cleanup old components

* correc copy paste error

LibreNMS/Util/Url.php

@@ -129,6 +129,10 @@ class Url
      */
     public static function portLink($port, $text = null, $type = null, $overlib = true, $single_graph = false)
     {
+        if ($port === null) {
+            return $text;
+        }
+
         $label = Rewrite::normalizeIfName($port->getLabel());
         if (! $text) {
             $text = $label;