Display verbose packaging errors to the user
    
    Sometimes packaging has more information about an error. These are
    logged, but not all users know how to read the logs. This adds a
    clickable info bar to the source spoke and storage for errors in the
    payload.verbose_errors list.
    
    Now when there is a problem fetching .treeinfo or fetching metadata the
    exact error will be visible when the info bar is clicked.