Remove .trim() from dropdown widget JS

Maybe a bit weird request :D

From #2815269: Dropdown does not remove HTML when creating options:

-        $option.html($link.html());
+        $option.html($link.text().trim());

The issue is that .trim() removes non-breaking spaces as well.

At our project we use non-breaking spaces to display facets in hierarchy. Not sure whether there can be other use cases, but it will do absolutely no harm if we remove .trim(). Browsers will trim leading/ending spaces anyway when displaying text from select options.