Xdata: Expose proxy key to client when Proxy is lazy loaded

BIZ BIZ Feature Requests
1

Now if I ask records which have reference with Lazy Proxy like this

    [Association([TAssociationProp.Lazy], CascadeTypeAllButRemove - [TCascadeType.Flush])]
    [JoinColumn('Main', [], 'Id')]
    FMain: proxy< TMain >;

I get output json (11 = id of detail field)
"Main@xdata.proxy": "Detail(11)/Main"
without lazy it's
"Main@xdata.ref": "main(2)"
Where 2 is proper Id of master stored in Detail table
Problem here is that without lazy outer join is generated.

So Add a way to delivery real value stored in table to client when using Lazy proxy. Also add support to XData client so generated object gets the value.