access active link state in the context

[fly1ted]

I had a use-case where I needed a simple way to change an element inside {{#link-to}} so not to write additional css targeting that list. Exposing this helps to solve this.

{{#link-to 'foo' classNames="" as |l|}}
  <i class="Icon Icon--messages"></i>
  {{#unless l.active}}
    <span class="">
      bar
    </span>
  {{/unless}}
{{/link-to}}

[bekzod]

I think #15835 is less obtrusive way which going for RFC too

[locks]

Superseded by #15835, thanks!