Import latest app updates from streamline

An updated set of source files and initialization was provided by streamline to
address issues observed during initial testing. These files have been updated in
order to generate a new set of app images.

docker/streamline-src/vendor/symfony/console/Command/SignalableCommandInterface.php

@@ -1,34 +0,0 @@
-<?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\Command;
-
-/**
- * Interface for command reacting to signal.
- *
- * @author Grégoire Pineau <lyrixx@lyrix.info>
- */
-interface SignalableCommandInterface
-{
-    /**
-     * Returns the list of signals to subscribe.
-     */
-    public function getSubscribedSignals(): array;
-
-    /**
-     * The method will be called when the application is signaled.
-     *
-     * @param int|false $previousExitCode
-     *
-     * @return int|false The exit code to return or false to continue the normal execution
-     */
-    public function handleSignal(int $signal, /* int|false $previousExitCode = 0 */);
-}