#59953888 Added submitted state to SurveyInvitation, don't show best_in_place if submitted
Make it clear this controls rendering, not actual responding, since f58c058af5840c7294987b9b70490a9ce22ba894
Added SurveyUser#state method to provide a canonical state a user is in for a survey
#59952680 Render submit/results button and optional alert on survey response page