Energy2D: Implement XML -> JSON parser in JS (node.js)

[#52940627]

So we can use validator and metadata during conversion, also convert
only useful properties instead of all available in Java version.
Energy2D: Add 'convert-models' script for running XML->JSON conversion

[#52940627]
Energy2D: Remove unnecessary options from metadata

[#52940627]
Energy2D: Update model JSONs after as new conversion script is used

[#52940627]

The main difference is that all default values are provided and there
is no unnecessary options.
Energy2D: Limit convert-to-json.rb script to generation of interactives

[#52940627]

Also change its name to generate-interactives.rb