As a developer I want to fetch the data of a property, so I can use elements I need in my application

GET /entities/properties/{property_id}

Can be seen as a counterpart of GET /entities/items/{item_id}

The structure of data in response will be similar to item data structure with additional top-level data-type field carrying the data on the property's data type. There will be no sitelinks field and the Action API's claims field will be renamed to statements.

Note:

• authentication and authorization - same treatment as existing for GET item data endpoint.
• sitelinks do not exist on properties
• redirects do not exist for properties

To not include in this story (will be done later on)

• handling conditional HTTP headers
• _fields parameter to define what property data elements to include in the API response

Error cases to consider:

Any authentication/authorization errors -- rely on the behaviour of the Mediawiki REST API "framework".