[WPF] Fix reallocation issue
[WPF] Fix reallocation issue

Reallocate the root widget when a window is rearranged.

iainx/xwt,hwthomas/xwt,mminns/xwt,directhex/xwt,antmicro/xwt,residuum/xwt,akrisiun/xwt,lytico/xwt,steffenWi/xwt,mminns/xwt,TheBrainTech/xwt,hamekoz/xwt,mono/xwt,cra0zy/xwt,sevoku/xwt