Set values for StandardContext in Frontend

Now that we have everything set up to hash user_id we need to provide the values as well to the events. For BE we're mostly covered, but we have not set namespace/project and user for the StandardContext that is provided to the Frontend. (see #338150 (closed))

  1. We currently read the StandardContext
  2. Which gets provided and set in _snowplow.html.haml
  3. For this StandardContext we want to set the project, namespace and current_user (if available)
Edited by Axel García