Updated mediawiki/extensions
Project: mediawiki/extensions/MobileFrontend  cdf23f8352bcf082b498ccb255e9312626bfb936

Promote mediawiki-ui buttons to stable in mobile

Also remove old button styles now that we use mw-ui-button

Change-Id: Iea3a0c22a866694e20be6879a38b434479a889ab