SVGHMI: add support for "reference" and "frame" rectangles to spread-out ovelapping elements.
When HMI become complicated, designer needs to spread-out ovelapping elements
in order to unclutter drawing and facilitate maintenance.
<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema" URI_location="PYRO://127.0.0.1:61427">
<TargetType/>
<Libraries Enable_SVGHMI_Library="true"/>
</BeremizRoot>