ASP.NET Core client side Blazor applications can't be run in VSCode

This was originally reported over in https://github.com/aspnet/AspNetCore/issues/9451 and it seems that the dialog to add build assets to the project can’t detect Blazor client side applications because they’re not true runnable applications on their own.

To fix this there’s two steps:

1. Make runnable project detection understand Blazor client side applications
2. Update the run .net core console app to utilize dotnet run --no-build instead of dotnet *.dll. The distinction about using dotnet run enables the Blazor project to hijack the run process and properly boot a runnable application.

/cc @danroth27

[gregg-miskelly]

dotnet run will launch the target in a child process. The .NET Debugging APIs have no support for child process debugging.

[gregg-miskelly]

Here are my suggestions:

1. Don’t do anything right now in terms of launch.json generation. We can leave this bug open to consider doing something someday for it.
2. Update the documentation to point point at running the dotnet watch task.