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/console/ConsoleEvents.php

@@ -0,0 +1,72 @@
+<?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\Console;
+
+use Symfony\Component\Console\Event\ConsoleCommandEvent;
+use Symfony\Component\Console\Event\ConsoleErrorEvent;
+use Symfony\Component\Console\Event\ConsoleSignalEvent;
+use Symfony\Component\Console\Event\ConsoleTerminateEvent;
+
+/**
+ * Contains all events dispatched by an Application.
+ *
+ * @author Francesco Levorato <git@flevour.net>
+ */
+final class ConsoleEvents
+{
+    /**
+     * The COMMAND event allows you to attach listeners before any command is
+     * executed by the console. It also allows you to modify the command, input and output
+     * before they are handed to the command.
+     *
+     * @Event("Symfony\Component\Console\Event\ConsoleCommandEvent")
+     */
+    public const COMMAND = 'console.command';
+
+    /**
+     * The SIGNAL event allows you to perform some actions
+     * after the command execution was interrupted.
+     *
+     * @Event("Symfony\Component\Console\Event\ConsoleSignalEvent")
+     */
+    public const SIGNAL = 'console.signal';
+
+    /**
+     * The TERMINATE event allows you to attach listeners after a command is
+     * executed by the console.
+     *
+     * @Event("Symfony\Component\Console\Event\ConsoleTerminateEvent")
+     */
+    public const TERMINATE = 'console.terminate';
+
+    /**
+     * The ERROR event occurs when an uncaught exception or error appears.
+     *
+     * This event allows you to deal with the exception/error or
+     * to modify the thrown exception.
+     *
+     * @Event("Symfony\Component\Console\Event\ConsoleErrorEvent")
+     */
+    public const ERROR = 'console.error';
+
+    /**
+     * Event aliases.
+     *
+     * These aliases can be consumed by RegisterListenersPass.
+     */
+    public const ALIASES = [
+        ConsoleCommandEvent::class => self::COMMAND,
+        ConsoleErrorEvent::class => self::ERROR,
+        ConsoleSignalEvent::class => self::SIGNAL,
+        ConsoleTerminateEvent::class => self::TERMINATE,
+    ];
+}