There are various components that in Flow that should be polished up
and pushed into MediaWiki UI. We should polish these up as much as
possible, thinking about how they render in mobile, whether they are
important and get them upstreamed to core. Flow also ships its own
version of MediaWiki UI buttons (flow-ui-button). We will have to
standardise and improve MediaWiki UI where necessary before even
thinking of shipping these styles to mobile. MediaWiki UI is already
loaded on mobile so this would be an easy win.