Filtering based on subType `DeviceAppManagement.MobileApps.GraphWin32LobApp`

Describe the bug
Not really a bug I guess more wrong expectations. I would expect that DeviceAppManagement.MobileApps.GraphWin32LobApp would have a GetAsync(...) method that would request all mobile apps of that type.

To Reproduce
Steps to reproduce the behavior:

1. Create GraphServiceClient
2. Try to load all Win32LobApps
3. Fail miserably

Expected behavior
I expected that the Type cast to GraphWin32LobApp would also set the required filter on the mobileApps.

If you want to get all Win32LobApps, you would need to do:

graphServiceClient.DeviceAppManagement.MobileApps.GetAsync((config) => {
    config.QueryParameters.Filter = "isof('microsoft.graph.win32LobApp')";
    ...
});

And then cast the results (if any) to the desired type.

I would expect this to be available in the SDK as DeviceAppManagement.MobileApps.GraphWin32LobApp.GetAsync(...)

Additional context

This is not specific for just this type. There is a lot of Type casting going on and I'm hoping for a solution for all those cases.

Start with GraphServiceClient.DeviceAppManagement.MobileApps.GetAsync and the GraphWin32LobApp access pattern described in the issue. Investigate how subtype casts and the mobileApps filter are represented in the SDK, then define what consistent typed retrieval should look like across the other casting cases before validating the behavior.