Fixes #1301: Enable read the property without value

[xuzhg]

Fixes #1301 Enable read property without value

ODL supports to read the property without value. Here's an example:

{
    "@odata.context":"http://localhost/$metadata#Customers/$entity",
    "CustomerID": 17,
    "[email protected]":123,
    "[email protected]":true,
    "Location": { "Street":"154TH AVE"}
}

where, the property 'Name' only contains the instance annotations.

ODL can read the above properties and output the 'ODataReaderState.NestedPropertyInfo' in the reading pipeline.

This PR is to handle ''ODataReaderState.NestedPropertyInfo' and hold the 'ODataPropertyInfo' instances into a container, and provides an solution for end users to access such properties by customizing the deserializer.

It's a PR to retrieve the reading process out of the whole instance annotation features and try to make it small enough but a complete feature.

Make the PR as small as possible to help the code reviewing.