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/composer/autoload_real.php

@@ -0,0 +1,50 @@
+<?php
+
+// autoload_real.php @generated by Composer
+
+class ComposerAutoloaderInit379a36e429894b61b55afc3b84fa116a
+{
+    private static $loader;
+
+    public static function loadClassLoader($class)
+    {
+        if ('Composer\Autoload\ClassLoader' === $class) {
+            require __DIR__ . '/ClassLoader.php';
+        }
+    }
+
+    /**
+     * @return \Composer\Autoload\ClassLoader
+     */
+    public static function getLoader()
+    {
+        if (null !== self::$loader) {
+            return self::$loader;
+        }
+
+        require __DIR__ . '/platform_check.php';
+
+        spl_autoload_register(array('ComposerAutoloaderInit379a36e429894b61b55afc3b84fa116a', 'loadClassLoader'), true, true);
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(__DIR__));
+        spl_autoload_unregister(array('ComposerAutoloaderInit379a36e429894b61b55afc3b84fa116a', 'loadClassLoader'));
+
+        require __DIR__ . '/autoload_static.php';
+        call_user_func(\Composer\Autoload\ComposerStaticInit379a36e429894b61b55afc3b84fa116a::getInitializer($loader));
+
+        $loader->register(true);
+
+        $filesToLoad = \Composer\Autoload\ComposerStaticInit379a36e429894b61b55afc3b84fa116a::$files;
+        $requireFile = \Closure::bind(static function ($fileIdentifier, $file) {
+            if (empty($GLOBALS['__composer_autoload_files'][$fileIdentifier])) {
+                $GLOBALS['__composer_autoload_files'][$fileIdentifier] = true;
+
+                require $file;
+            }
+        }, null, null);
+        foreach ($filesToLoad as $fileIdentifier => $file) {
+            $requireFile($fileIdentifier, $file);
+        }
+
+        return $loader;
+    }
+}