Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/guzzlehttp/psr7/src/UriComparator.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace GuzzleHttp\Psr7;
+
+use Psr\Http\Message\UriInterface;
+
+/**
+ * Provides methods to determine if a modified URL should be considered cross-origin.
+ *
+ * @author Graham Campbell
+ */
+final class UriComparator
+{
+    /**
+     * Determines if a modified URL should be considered cross-origin with
+     * respect to an original URL.
+     */
+    public static function isCrossOrigin(UriInterface $original, UriInterface $modified): bool
+    {
+        if (\strcasecmp($original->getHost(), $modified->getHost()) !== 0) {
+            return true;
+        }
+
+        if ($original->getScheme() !== $modified->getScheme()) {
+            return true;
+        }
+
+        if (self::computePort($original) !== self::computePort($modified)) {
+            return true;
+        }
+
+        return false;
+    }
+
+    private static function computePort(UriInterface $uri): int
+    {
+        $port = $uri->getPort();
+
+        if (null !== $port) {
+            return $port;
+        }
+
+        return 'https' === $uri->getScheme() ? 443 : 80;
+    }
+
+    private function __construct()
+    {
+        // cannot be instantiated
+    }
+}