[#65595802] Changes traveler_characteristic and traveler_accommodation to characteristic and accommodation, respectively
[#65595802] Changes user_traveler_characteristics_map to user_characteristic and changes user_traveler_accommodations_map to user_accommodation
[#65595802] Changes service_traveler_characteristics_map to service_characteristic and change servce_traveler_accommodations_map to service_accommodation
[#65595802] Changes service_traveler_characteristics_map to service_characteristic and change servce_traveler_accommodations_map to service_accommodation
[Fixes#65595802] Updates tests to reflect characteristics and accommodations refactoring.