new property AutoSize in TMSFMXGrid

same functionality as VCL TAdvStringGrid.Autosize

The property only applies auto-sizing once during load time of the TAdvStringGrid. This functionality is already available in the TTMSFMXGrid:

procedure TForm1.TMSFMXGrid1ApplyStyleLookup(Sender: TObject);
begin
TMSFMXGrid1.AutoSizeColumns(True);
end;

This feature was implemented.