Return empty TryNewDot NVP as object

[Julesssss]

Problem

As discussed here, to unblock the ReactNative HybridApp signin page we need to modify the backend onyx response for authentication API calls.

Solution

Instead of returning an empty array we need to return an empty object from the following commands:

• BeginSignIn
• SignInUser

Then make sure to run these tests again

[Julesssss]

Draft PR here.