Improved usage detection across includes, extends and embeds.

[OwlyCode]

This adds support for template resolution by twigcs, allowing usage detection across multiple files.

For instance, the following files:

# child.html.twig
{{ foo }}
{% set unused_child = 1 %}

{% set foo = 1 %}
{% set unused_parent = 2 %}

{% embed 'child.html.twig' %} 

Would not mark foo as unused.

This feature is only available when using file based configuration as it requires the user to take some decisions on how to load the templates. The most simple form would be:

<?php
use FriendsOfTwig\Twigcs\TemplateResolver\NamespacedResolver;
return \FriendsOfTwig\Twigcs\Config\Config::create()
    // ...
    ->setTemplateResolver(new FileResolver(__DIR__))
    ->setRuleSet(FriendsOfTwig\Twigcs\Ruleset\Official::class)
;