Fix regression when setting children of InfofulBoxAutoSize
Fix regression when setting children of InfofulBoxAutoSize

Previously, setting children would not clear all previous children.
Now that it does, we need to override Content to provide existing
code with previous functionality.

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