Message internationalisation

Example notification with message ids for internationalization purposes

{
    type : "prompt",  // other possible types are "configuration" or "resource."
    importance : "8",  // importance level with range [1, ..., 10].
    target : {
        type : "app",  
        id : "provider_id-actor_id-generator_id"   // unique id to adress a particular app.
    },
    content : {
        messageId : "sug:sug1"  // message with id sug:sug1 is of type suggestion.
        messageParams : {
            "activities": ["act:add"], // ids of activity components
            "objects": ["obj:concept2"], // ids of activity components
            "targets": ["tar:tyc"], // ids of activity components
            "goals": [], // ids of activity components
            "values": ["#Value"] // a specific value
        }
    }
}