[Mac] Improve TextLayout backend to better match its Gtk counterpart
[Mac] Improve TextLayout backend to better match its Gtk counterpart

The line height calculations and newline behavior now match the Gtk backend

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