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/UnableToCheckExistence.php

@@ -1,26 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace League\Flysystem;
-
-use RuntimeException;
-use Throwable;
-
-class UnableToCheckExistence extends RuntimeException implements FilesystemOperationFailed
-{
-    final public function __construct(string $message = "", int $code = 0, ?Throwable $previous = null)
-    {
-        parent::__construct($message, $code, $previous);
-    }
-
-    public static function forLocation(string $path, Throwable $exception = null): static
-    {
-        return new static("Unable to check existence for: {$path}", 0, $exception);
-    }
-
-    public function operation(): string
-    {
-        return FilesystemOperationFailed::OPERATION_EXISTENCE_CHECK;
-    }
-}