SVGHMI: Add list of HMI tree path in a JS array, so that we can use it for multiple purpose :
- display name of edited variable in keypads (currently wrong in relative pages)
- have some variable that hold basename of current relative page HMI_NODE's path
- propose some list of names in DropDown when selecting a relative page to jump to, without having to instancite many jump widgets.

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