Autocomplete and search return one result per building

A query that does not name a unit now gets a building back once instead of once per unit, and a result for a unit carries it in the address.

• GET /autocomplete and GET /search now collapse one building's units the same way they already collapsed one address held by several sources: a query that does not name a unit gets the building back once.
• A query that does name a unit (5-200 Elgin St, unit 5) still keeps every unit apart, and the result's name carries it (5-200 Elgin St, Ottawa), along with address.unit.