Remove legacy auth usage of $_SESSION (#10491)

* Remove auth use of $_SESSION

Will break plugins that depend on $_SESSION, Weathermap was already fixed.
Port them to use Auth::check()/Auth::user()/Auth:id()

* revert accidental replacement

includes/html/graphs/global/auth.inc.php

@@ -1,7 +1,5 @@
 <?php
 
-use LibreNMS\Authentication\LegacyAuth;
-
-if (LegacyAuth::user()->hasGlobalRead()) {
+if (Auth::user()->hasGlobalRead()) {
     $auth = 1;
 }