Ad-hoc unplanned workout logging in mobile app

Ad-hoc Unplanned Sessions: aka Completed Sessions that require no planned session

Add a way for athletes in the mobile app to log and complete unplanned workouts that are not part of their assigned program: a button such as “complete unplanned workout” that lets them build the workout in realtime, selecting the exercise, set/rep schemes and target actuals as they go. Currently workouts performed outside of an assigned program are lost because athletes have no way of logging them, e.g. athletes who walk into gyms and perform non planned workouts.