Remove the top level Components folder from the Blazor WebAssembly Standalone App template

[danroth27]

In the Blazor Web App template we only include the top level Components folder in the server project. It makes sense in the server project because you might have a lot of other stuff in that project, like MVC controllers, SignalR hubs, etc. In the client project we don't have the top level Components folder because the client project is Blazor specific. The Blazor WebAssembly Standalone App project template is also Blazor specific, but it has the unnecessary top level Components folder. We should make the Blazor WebAssembly Standalone App folder structure consistent with the structure of the client project in the Blazor Web App template.