[imp] standarise layout vars comments + calls from plugins

This makes both plugins to use the same layout data with the same layout comments. We could even build a `JPluginIcon` to extend with a `renderLayout()` method that will save us some code but I don't think it worths the effort now as we have to check the `$context` in the plugin. It will save us like 8-10 lines of code. 

I did also a JS cleanup to improve readability as we don't need the `\n` & `\t` to get it rendered properly on browsers.