some more unit tests on xml info parser

drop files_external tests from autotest - they will be executed with autotest-external.sh which is coming

Currently there is no AppFramework way to modify cookies, which makes it unusable for quite some use-cases or results in untestable code.

This PR adds some basic functionalities to add and invalidate cookies.

Usage:
```php
$response = new TemplateResponse(...);
$response->addCookie('foo', 'bar');
$response->invalidateCookie('foo');
$response->addCookie('bar', 'foo', new \DateTime('2015-01-01 00:00'));
```

Existing cookies can be accessed with the AppFramework using `$this->request->getCookie($name)`.

This is unused legacy code. Let it die with ~~~honor~~ fire.

Fixes https://github.com/owncloud/core/issues/12346

Fixes https://github.com/owncloud/core/issues/12347

This reverts commit 09fd34ee.

The result of the listener should then be empty and can be removed

add postfix

This lead to a lot of confusion in the past and did not really offer any value. Let's remove the port check therefore. (it's anyways not really a part of the domain)

Fixes https://github.com/owncloud/core/issues/12150 and https://github.com/owncloud/core/issues/12123 and also a problem reported by @DeepDiver1975.

Conflicts:
	lib/private/request.php

THX @schiesbn
(I should setup a mail server on my local system...)

This patch wil warn the user of the consequences when resetting the password and requires checking a checkbox (as we had in the past) to reset a password.

Furthermore I updated the code to use our new classes and added some unit tests for it 👯

Fixes https://github.com/owncloud/core/issues/11438