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/owen-it/laravel-auditing/src/Models/Audit.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace OwenIt\Auditing\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+/**
+ * @property string $tags
+ * @property string $event
+ * @property array $new_values
+ * @property array $old_values
+ * @property mixed $user
+ * @property mixed $auditable.
+ */
+class Audit extends Model implements \OwenIt\Auditing\Contracts\Audit
+{
+    use \OwenIt\Auditing\Audit;
+
+    /**
+     * {@inheritdoc}
+     */
+    protected $guarded = [];
+
+    /**
+     * {@inheritdoc}
+     */
+    protected $casts = [
+        'old_values'   => 'json',
+        'new_values'   => 'json',
+        // Note: Please do not add 'auditable_id' in here, as it will break non-integer PK models
+    ];
+
+    public function getSerializedDate($date)
+    {
+        return $this->serializeDate($date);
+    }
+}