Person entity display name

- Pass only first name and last name from entity
- Add PersonViewUtils.person_entity_display_name
- Take display name into use in Admin transactions view
- Take display name into use in free conversations
Show removed user in inbox
Show display_name in preauthorize action
Preauthorize controller uses display_name
Make delete_listings available outside module
Transaction view and message view shows "Removed user"
Copy texts and translations
Copy for multimembership delete
No ongoing transactions
Use new delete methods in PeopleController
Show removed user in testimonials and comments
Remove link to listing in admin transaction view
No link to listing from inbox
Remove link from transaction to listing
Ignore user's deleted listings