Make $_REQUEST processing independent of sub-calls

- Move HTTPInputData::process() into App::runFrontend()
- Pass $_REQUEST (including processed Input) to every Module method
- Delete $_POST parameters at Module post() calls because of $_REQUEST

src/Module/Contact.php

@@ -91,7 +91,7 @@ class Contact extends BaseModule
 		DI::baseUrl()->redirect($redirectUrl);
 	}
 
-	protected function post(array $request = [], array $post = [])
+	protected function post(array $request = [])
 	{
 		if (!local_user()) {
 			return;