Translates a with_scope call for select fields

It makes it easier to write liquid for using with_scope on select fields - you just use the name of the option instead of needing to know it's id:

```liquid
<h1>News posts:</h1>
{%with_scope category: 'news' %}
    {%for post in models.posts%}
    {{post.name}}

    {%endfor%}
  {%endwith_scope%}
```