ListToolGroup: Re-clip when expanding/collapsing
ListToolGroup: Re-clip when expanding/collapsing

This fixes a bug where a ListToolGroup in a bottom toolbar
close to the bottom of the viewport (which you get by
increasing the font size on the toolbar demo) would
not resize itself correctly when "More" was clicked, with
tools spilling out of the toolgroup onto the toolbar.

Change-Id: I24b123b4f005adfb59942048d298152bbeec9e0d

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui