TitleInputWidget: Correct links when 'relative' option used

TitleInputWidget: Correct links when 'relative' option used

Previously, the links in the suggestions dropdown also pointed to
the relative version, e.g. "/wiki/Foo" instead of "/wiki/Template:Foo".

This also corrects missing dependency for mediawiki.util, which
is no longer used directly (although mediawiki.Title depends on it,
so the code worked correctly in spite of missing dependency).

Follow-up to ddca1c657e21bd49c01ead2e5e0fbcdb9ee26255.

Change-Id: I8f9293636c597cd617e68b4c238d7424915cf351