Fix ScrollContainer lagging behind by one frame
Fix ScrollContainer lagging behind by one frame

The internal size the ScrollContainer used to make decisions about
the scroll range, scrollbar size, etc. was outdated by one frame
because it was updated before its children.

paparony03/osu-framework,smoogipooo/osu-framework,ZLima12/osu-framework,ppy/osu-framework,peppy/osu-framework,DrabWeb/osu-framework,EVAST9919/osu-framework,peppy/osu-framework,ppy/osu-framework,ZLima12/osu-framework,default0/osu-framework,Nabile-Rahmani/osu-framework,naoey/osu-framework,DrabWeb/osu-framework,Nabile-Rahmani/osu-framework,EVAST9919/osu-framework,paparony03/osu-framework,default0/osu-framework,Tom94/osu-framework,DrabWeb/osu-framework,smoogipooo/osu-framework,peppy/osu-framework,EVAST9919/osu-framework,ppy/osu-framework,EVAST9919/osu-framework,naoey/osu-framework,Tom94/osu-framework