Azure.Core 2.0: Reimplement NoValueResponse<T>so it doesn't duplicate the response field

[annelo-msft]

The shared source file NoValueResponse should not add a new field _response when it can get it from the base OutputMessage type in ClientModel. Today, because it is internal shared source used across many libraries, it is too complicated to implement this.

We should come back and reimplement it to get the performance gain when time allows as part of the Azure.Core 2.0 work.

It could look like this: https://github.com/Azure/azure-sdk-for-net/blob/a4c872765cf791b564ca5d1abb27b96844d7ff25/sdk/core/Azure.Core/src/Shared/NoValueResponseOfT.cs