Get rid of ve.init.mw.ViewPageTarget-vector-hd.css and use a media query instead

This will mean it will be more obvious if making a change to the SD or HD version
that an equivalent adjustment may be needed.

Change-Id: I6129220839ef55017fe69d723524ecdf6cf0234f
Merge "Get rid of ve.init.mw.ViewPageTarget-vector-hd.css and use a media query instead"