Add PoliciesConfiguration to handle server policies

src/Socialbox/Classes/Configuration/PoliciesConfiguration.php

@@ -0,0 +1,21 @@
+<?php
+
+    namespace Socialbox\Classes\Configuration;
+
+    class PoliciesConfiguration
+    {
+        private int $maxSigningKeys;
+
+        public function __construct(array $data)
+        {
+            $this->maxSigningKeys = $data['max_signing_keys'];
+        }
+
+        /**
+         * @return int
+         */
+        public function getMaxSigningKeys(): int
+        {
+            return $this->maxSigningKeys;
+        }
+    }