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/event-dispatcher-contracts/Event.php

@@ -1,51 +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\Contracts\EventDispatcher;
-
-use Psr\EventDispatcher\StoppableEventInterface;
-
-/**
- * Event is the base class for classes containing event data.
- *
- * This class contains no event data. It is used by events that do not pass
- * state information to an event handler when an event is raised.
- *
- * You can call the method stopPropagation() to abort the execution of
- * further listeners in your event listener.
- *
- * @author Guilherme Blanco <guilhermeblanco@hotmail.com>
- * @author Jonathan Wage <jonwage@gmail.com>
- * @author Roman Borschel <roman@code-factory.org>
- * @author Bernhard Schussek <bschussek@gmail.com>
- * @author Nicolas Grekas <p@tchwork.com>
- */
-class Event implements StoppableEventInterface
-{
-    private bool $propagationStopped = false;
-
-    public function isPropagationStopped(): bool
-    {
-        return $this->propagationStopped;
-    }
-
-    /**
-     * Stops the propagation of the event to further event listeners.
-     *
-     * If multiple event listeners are connected to the same event, no
-     * further event listener will be triggered once any trigger calls
-     * stopPropagation().
-     */
-    public function stopPropagation(): void
-    {
-        $this->propagationStopped = true;
-    }
-}