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/Api/Mastodon/FollowRequests.php

@@ -42,7 +42,7 @@ class FollowRequests extends BaseApi
 	 * @see https://docs.joinmastodon.org/methods/accounts/follow_requests#accept-follow
 	 * @see https://docs.joinmastodon.org/methods/accounts/follow_requests#reject-follow
 	 */
-	protected function post(array $request = [], array $post = [])
+	protected function post(array $request = [])
 	{
 		self::checkAllowedScope(self::SCOPE_FOLLOW);
 		$uid = self::getCurrentUserID();