Make BaseModule a real entity

- Add all dependencies, necessary to run the content (baseUrl, Arguments)
- Encapsulate all POST/GET/DELETE/PATCH/PUT methods as protected methods inside the BaseModule
- Return Module content ONLY per `BaseModule::run()` (including the Hook logic there as well)

src/Module/OpenSearch.php

@@ -36,7 +36,7 @@ class OpenSearch extends BaseModule
 	/**
 	 * @throws \Exception
 	 */
-	public function rawContent()
+	protected function rawContent(array $request = [])
 	{
 		header('Content-type: application/opensearchdescription+xml');