[FEATURE] Allow PHP as fixture data provider

[sascha-egerer]

Add support for PHP files as fixture data provider like ComponentName.fixture.php

Resolves #109

[sascha-egerer]

I have also a neat helper that does render a component that than can be passed to a slot.

Looks like this:

return [
    'default'  => [
        'firstAttribute' => 'value',
        'mySlot' => $fixtureProvider->renderComponentTagWithFixture(componentIdentifier: 'component.abc', fixtureIdentifier: 'default'),
    ]
];

If this one gets merged i may also contribute this helper if you think it does make sende.