SVGHMI: allow multiple variables and formatting in Display widget. Formatting is printf style and given as first argument. If no formating is given as widget argument, space separated.

<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot URI_location="LOCAL://">
  <TargetType/>
  <Libraries Enable_SVGUI_Library="true" Enable_Python_Library="true"/>
</BeremizRoot>