Add remaining YLPBusiness fields

There are more fields returned in the v3 business that aren't exposed by the current `YLPBusiness`:
* `is_closed`
* `price`
* `photos`
* `hours`

Note that these fields are only provided on the business returned from the business endpoint (i.e. not from search), so we might want to only provide them on a subclass of `YLPBusiness` used in the business endpoint's response.