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/psr/event-dispatcher/src/StoppableEventInterface.php

@@ -1,26 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace Psr\EventDispatcher;
-
-/**
- * An Event whose processing may be interrupted when the event has been handled.
- *
- * A Dispatcher implementation MUST check to determine if an Event
- * is marked as stopped after each listener is called.  If it is then it should
- * return immediately without calling any further Listeners.
- */
-interface StoppableEventInterface
-{
-    /**
-     * Is propagation stopped?
-     *
-     * This will typically only be used by the Dispatcher to determine if the
-     * previous listener halted propagation.
-     *
-     * @return bool
-     *   True if the Event is complete and no further listeners should be called.
-     *   False to continue calling listeners.
-     */
-    public function isPropagationStopped() : bool;
-}