Update Twig from 1.35.0 to 1.42.4 (PHP 5.5 is now required!)

This fixes some errors on PHP 7.4 and contains even more fixes
Also bumped PHP version to 5.5 as Twig requires it.

system/libs/Twig/Extension/StringLoaderExtension.php

@@ -0,0 +1,54 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Twig\Extension {
+use Twig\TwigFunction;
+
+/**
+ * @final
+ */
+class StringLoaderExtension extends AbstractExtension
+{
+    public function getFunctions()
+    {
+        return [
+            new TwigFunction('template_from_string', 'twig_template_from_string', ['needs_environment' => true]),
+        ];
+    }
+
+    public function getName()
+    {
+        return 'string_loader';
+    }
+}
+
+class_alias('Twig\Extension\StringLoaderExtension', 'Twig_Extension_StringLoader');
+}
+
+namespace {
+use Twig\Environment;
+use Twig\TemplateWrapper;
+
+/**
+ * Loads a template from a string.
+ *
+ *     {{ include(template_from_string("Hello {{ name }}")) }}
+ *
+ * @param string $template A template as a string or object implementing __toString()
+ * @param string $name     An optional name of the template to be used in error messages
+ *
+ * @return TemplateWrapper
+ */
+function twig_template_from_string(Environment $env, $template, $name = null)
+{
+    return $env->createTemplate((string) $template, $name);
+}
+}