Required text needs to be inverse in settings tray

[macburgee1]

Currently, when a field is designated as required, the required markup is correctly added by unl_five_preprocess_form_element(); however, in the settings tray, it needs to displayed in inverse:

In unl_five_preprocess_form_element(), it's not possible to know if the settings tray is involved not. For that matter, I'm not sure if there's a good programmatic way to conditionally add the dcf-inverse class. It might be the case where CSS is the solution.