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/CalculateChecksumFromStream.php

@@ -1,30 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace League\Flysystem;
-
-use function hash_final;
-use function hash_init;
-use function hash_update_stream;
-
-trait CalculateChecksumFromStream
-{
-    private function calculateChecksumFromStream(string $path, Config $config): string
-    {
-        try {
-            $stream = $this->readStream($path);
-            $algo = (string) $config->get('checksum_algo', 'md5');
-            $context = hash_init($algo);
-            hash_update_stream($context, $stream);
-
-            return hash_final($context);
-        } catch (FilesystemException $exception) {
-            throw new UnableToProvideChecksum($exception->getMessage(), $path, $exception);
-        }
-    }
-
-    /**
-     * @return resource
-     */
-    abstract public function readStream(string $path);
-}