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/league/flysystem/src/UnreadableFileEncountered.php

@@ -1,28 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace League\Flysystem;
-
-use RuntimeException;
-
-final class UnreadableFileEncountered extends RuntimeException implements FilesystemException
-{
-    /**
-     * @var string
-     */
-    private $location;
-
-    public function location(): string
-    {
-        return $this->location;
-    }
-
-    public static function atLocation(string $location): UnreadableFileEncountered
-    {
-        $e = new static("Unreadable file encountered at location {$location}.");
-        $e->location = $location;
-
-        return $e;
-    }
-}