Patients’ persistent symptoms, clinician demographics and geo-economic factors are associated with choice of therapy for hypothyroidism by European thyroid specialists: The “THESIS”* collaboration (*<i>T</i>reatment of <i>H</i>ypothyroidism in Europe by <i>S</i>pecialists, an <i>I</i>nternational <i>S</i>urvey)