performance improvements (#2329)

* remove work from constructor
* refactor twig extensions
* upgrade theme
* replace sub-request with direct template rendering

src/Twig/Runtime/WidgetExtension.php

@@ -0,0 +1,53 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Twig\Runtime;
+
+use App\Widget\WidgetException;
+use App\Widget\WidgetInterface;
+use App\Widget\WidgetService;
+use Twig\Extension\RuntimeExtensionInterface;
+
+final class WidgetExtension implements RuntimeExtensionInterface
+{
+    /**
+     * @var WidgetService
+     */
+    private $service;
+
+    public function __construct(WidgetService $service)
+    {
+        $this->service = $service;
+    }
+
+    /**
+     * @param WidgetInterface|string $widget
+     * @param array $options
+     * @return string
+     * @throws WidgetException
+     */
+    public function renderWidget($widget, array $options = [])
+    {
+        if (!($widget instanceof WidgetInterface) && !\is_string($widget)) {
+            throw new \InvalidArgumentException('Widget must either implement WidgetInterface or be a string');
+        }
+
+        if (\is_string($widget)) {
+            if (!$this->service->hasWidget($widget)) {
+                throw new \InvalidArgumentException(sprintf('Unknown widget "%s" requested', $widget));
+            }
+
+            $widget = $this->service->getWidget($widget);
+        }
+
+        $renderer = $this->service->findRenderer($widget);
+
+        return $renderer->render($widget, $options);
+    }
+}