Fix `RemoveAndDisposeImmediately()` failing for children of containers with overridden `Content`
Fix `RemoveAndDisposeImmediately()` failing for children of containers with overridden `Content`

ppy/osu-framework,peppy/osu-framework,peppy/osu-framework,ZLima12/osu-framework,smoogipooo/osu-framework,peppy/osu-framework,ZLima12/osu-framework,ppy/osu-framework,ppy/osu-framework,smoogipooo/osu-framework