[ALOY-1692] Unable use unicode characters in config.json

When using a unicode character in the config.json this is scaped when compiled and in the label shows \E and not the character itself. config.json in the global section:

"icon": {
  "bus":"\uE530"
}

When open the compiled version of CFG.js it shows like:

module.exports={"dependencies":{},"icon":{"bus":"\\uE530"}};

And using Alloy.CFG.icon.bus in the app result undesired apparence. Changing "\ \uE530" with "\uE530" the compiled version of the file CFG.js with liveview active works as expected.