Split extension into extension and runtime classes to match how the maker bundle creates twig extensions

src/Twig/Extension/IconExtension.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pcm\IconBundle\Twig\Extension;
+
+use Pcm\IconBundle\Twig\Runtime\IconRuntime;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFunction;
+
+final class IconExtension extends AbstractExtension
+{
+    /**
+     * @inheritDoc
+     */
+    public function getFunctions(): array
+    {
+        return [
+            new TwigFunction('icon', [IconRuntime::class, 'renderIcon'])
+        ];
+    }
+}