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/sebastian/exporter/README.md

@@ -0,0 +1,176 @@
+[![Latest Stable Version](https://poser.pugx.org/sebastian/exporter/v/stable.png)](https://packagist.org/packages/sebastian/exporter)
+[![CI Status](https://github.com/sebastianbergmann/exporter/workflows/CI/badge.svg)](https://github.com/sebastianbergmann/exporter/actions)
+[![Type Coverage](https://shepherd.dev/github/sebastianbergmann/exporter/coverage.svg)](https://shepherd.dev/github/sebastianbergmann/exporter)
+[![codecov](https://codecov.io/gh/sebastianbergmann/exporter/branch/main/graph/badge.svg)](https://codecov.io/gh/sebastianbergmann/exporter)
+
+# sebastian/exporter
+
+This component provides the functionality to export PHP variables for visualization.
+
+## Installation
+
+You can add this library as a local, per-project dependency to your project using [Composer](https://getcomposer.org/):
+
+```
+composer require sebastian/exporter
+```
+
+If you only need this library during development, for instance to run your project's test suite, then you should add it as a development-time dependency:
+
+```
+composer require --dev sebastian/exporter
+```
+
+## Usage
+
+Exporting:
+
+```php
+<?php
+use SebastianBergmann\Exporter\Exporter;
+
+$exporter = new Exporter;
+
+/*
+Exception Object &0000000078de0f0d000000002003a261 (
+    'message' => ''
+    'string' => ''
+    'code' => 0
+    'file' => '/home/sebastianbergmann/test.php'
+    'line' => 34
+    'previous' => null
+)
+*/
+
+print $exporter->export(new Exception);
+```
+
+## Data Types
+
+Exporting simple types:
+
+```php
+<?php
+use SebastianBergmann\Exporter\Exporter;
+
+$exporter = new Exporter;
+
+// 46
+print $exporter->export(46);
+
+// 4.0
+print $exporter->export(4.0);
+
+// 'hello, world!'
+print $exporter->export('hello, world!');
+
+// false
+print $exporter->export(false);
+
+// NAN
+print $exporter->export(acos(8));
+
+// -INF
+print $exporter->export(log(0));
+
+// null
+print $exporter->export(null);
+
+// resource(13) of type (stream)
+print $exporter->export(fopen('php://stderr', 'w'));
+
+// Binary String: 0x000102030405
+print $exporter->export(chr(0) . chr(1) . chr(2) . chr(3) . chr(4) . chr(5));
+```
+
+Exporting complex types:
+
+```php
+<?php
+use SebastianBergmann\Exporter\Exporter;
+
+$exporter = new Exporter;
+
+/*
+Array &0 (
+    0 => Array &1 (
+        0 => 1
+        1 => 2
+        2 => 3
+    )
+    1 => Array &2 (
+        0 => ''
+        1 => 0
+        2 => false
+    )
+)
+*/
+
+print $exporter->export(array(array(1,2,3), array("",0,FALSE)));
+
+/*
+Array &0 (
+    'self' => Array &1 (
+        'self' => Array &1
+    )
+)
+*/
+
+$array = array();
+$array['self'] = &$array;
+print $exporter->export($array);
+
+/*
+stdClass Object &0000000003a66dcc0000000025e723e2 (
+    'self' => stdClass Object &0000000003a66dcc0000000025e723e2
+)
+*/
+
+$obj = new stdClass();
+$obj->self = $obj;
+print $exporter->export($obj);
+```
+
+Compact exports:
+
+```php
+<?php
+use SebastianBergmann\Exporter\Exporter;
+
+$exporter = new Exporter;
+
+// Array ()
+print $exporter->shortenedExport(array());
+
+// Array (...)
+print $exporter->shortenedExport(array(1,2,3,4,5));
+
+// stdClass Object ()
+print $exporter->shortenedExport(new stdClass);
+
+// Exception Object (...)
+print $exporter->shortenedExport(new Exception);
+
+// this\nis\na\nsuper\nlong\nstring\nt...\nspace
+print $exporter->shortenedExport(
+<<<LONG_STRING
+this
+is
+a
+super
+long
+string
+that
+wraps
+a
+lot
+and
+eats
+up
+a
+lot
+of
+space
+LONG_STRING
+);
+```