Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/symfony/finder/SplFileInfo.php

@@ -0,0 +1,82 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Finder;
+
+/**
+ * Extends \SplFileInfo to support relative paths.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class SplFileInfo extends \SplFileInfo
+{
+    private string $relativePath;
+    private string $relativePathname;
+
+    /**
+     * @param string $file             The file name
+     * @param string $relativePath     The relative path
+     * @param string $relativePathname The relative path name
+     */
+    public function __construct(string $file, string $relativePath, string $relativePathname)
+    {
+        parent::__construct($file);
+        $this->relativePath = $relativePath;
+        $this->relativePathname = $relativePathname;
+    }
+
+    /**
+     * Returns the relative path.
+     *
+     * This path does not contain the file name.
+     */
+    public function getRelativePath(): string
+    {
+        return $this->relativePath;
+    }
+
+    /**
+     * Returns the relative path name.
+     *
+     * This path contains the file name.
+     */
+    public function getRelativePathname(): string
+    {
+        return $this->relativePathname;
+    }
+
+    public function getFilenameWithoutExtension(): string
+    {
+        $filename = $this->getFilename();
+
+        return pathinfo($filename, \PATHINFO_FILENAME);
+    }
+
+    /**
+     * Returns the contents of the file.
+     *
+     * @throws \RuntimeException
+     */
+    public function getContents(): string
+    {
+        set_error_handler(function ($type, $msg) use (&$error) { $error = $msg; });
+        try {
+            $content = file_get_contents($this->getPathname());
+        } finally {
+            restore_error_handler();
+        }
+        if (false === $content) {
+            throw new \RuntimeException($error);
+        }
+
+        return $content;
+    }
+}