feat($resource): add support for wrapped responses

[stephenleicht]

$resource cannot handle a response that has the data you want wrapped in a object that has additional metadata.

for example if the response from the server is:

{
    "meta": {
        "total_count": 100
    },
    "items": [/*Some sort of list of objects*/]
}

You lose a lot of the cool $resource features because your resource is actually the 'items' field and not the entire response.

transformRepsponse does not work for this because if you pull out the 'items' field there you lose the meta field data.

response interceptor doesn't work because by the time you get it has already been decorated as a Resource object.

there should probably be an additional field in the action configuration to specify what field in the response should be decorated as a Resource.

[stephenleicht]

I don't know why, but it created a new thing when I submitted the pull request. #6139

[tbosch]

What are you doing with the meta data when you only would like to have the items in the resource?