MAPG-115 add new classes to store request data (get, post, session, etc.)

src/Interfaces/Request/ISession.php

@@ -0,0 +1,12 @@
+<?php namespace MapGuesser\Interfaces\Request;
+
+interface ISession
+{
+    public function has(string $key): bool;
+
+    public function get(string $key);
+
+    public function set(string $key, $value): void;
+
+    public function delete(string $key): void;
+}