Dynamic joins (includes) for resources

[fvanderflier]

Currently we are returning every related object for a resource. This is all good for a small app, but in larger app scenarios, can lead to long response times and crashes. Also, it makes granular permissions (per content-type) hard to implement.

We should find a way to allow the users of the api what to include in the related properties, via query-params. This should be taken in the request and passed down to some implementation. However this means that the current implementation (source generated data access in the controllers) needs to be removed and a more dynamic one should be provided in them.

Acceptance criteria

• All controllers should accept a query parameter for example:http://mydappiapi/auhtors?include=books, books.editions&...
• The controller will return only the included related data.