Cosmos: Stop nesting results in an extra JSON object

[roji]

Our basic Cosmos query looks like this:

SELECT c FROM root c

This produces results such as the following:

[
    {
        "c": {
            "id": "...",
            "Foo": 1,
        }
    },
    {
        "c": {
            "id": "...",
            "Foo": 2,
        }
    }
]

Instead, we could generate the following simpler star-based query:

SELECT VALUE c FROM root c

Which produces:

[
    {
        "id": "...",
        "Foo": 1,
    },
    {
        "id": "...",
        "Foo": 2,
    }
]

[ajcvickers]

Note: breaking change because it impacts raw queries.

[roji]

This creates issues since subqueries need to project out the bare object, rather than an object wrapping the object (interferes with query). We could have different logic for top-level projections (which are processed by the shaper) and subquery projections (which aren't), but we really should just do the right thing.