API response structure should be hierarchical instead of flat

I created a handful of api endpoints in 1.8 with a flat response structure like:

{
"response": [

{ "asn": "23", "cachegroupId": "69", "cachegroupName": "Foo_Cachegroup", "id": "60", "lastUpdated": "2016-10-13 12:31:43" }

]
}

Although this is fine, it makes it more difficult to test when using structures derived from the database. This structure is more friendly.

{
"response": [
{
"asn": "23",
"cachegroup":

{ "id": "69", "name": "Aberdeen_17802B_Ciscos" }

,
"id": "60",
"lastUpdated": "2016-10-13 12:31:43"
}
]
}

This nested structure needs to be applied to api endpoints related to asn, cachegroup, deliveryservice, phys_location, region, server and user.