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/Credits.php

@@ -32,7 +32,7 @@ use Friendica\DI;
  */
 class Credits extends BaseModule
 {
-	public function content(): string
+	protected function content(array $request = []): string
 	{
 		/* fill the page with credits */
 		$credits_string = file_get_contents('CREDITS.txt');