Provide a Get by ID SDK method which fetches VirtualMachine model and instance views in a single API call

There is currently no way to retrieve the combined model and instance views of a single Virtual Machine using a Get by ID API call in the SDK. The Virtual Machine Get REST API supports this using the $expand parameter:

https://docs.microsoft.com/en-us/rest/api/compute/virtualmachines/get

`Azure.virtualMachines().getById()` and `Azure.virtualMachines().getByIdAsync()` both call the Get API without the $expand parameter. The only way I've found to retrieve instance view details after calling getById() is to attempt to access one of the instance properties such as VirtualMachine.powerState(). This forces the calling code to make two sequential API calls to Azure.

It would be ideal to have a way in the SDK to retrieve both model and instance views in a single API call since the underlying REST API supports this mechanism.

まず Azure.virtualMachines().getById() と getByIdAsync() を REST Get 呼び出しまでたどり、次にリンクされている Virtual Machines Get API のドキュメントを読んで $expand のサポートを確認します。両方の SDK メソッドで、1 回の API 呼び出しによってモデルとインスタンスを結合したビューを取得できれば完了です。

索引モデルが issue の本文から書いたものです。