Identity MVC scaffolding does utilize scaffolded assets

[MackinnonBuck]

Summary

When scaffolding Identity UI into a project without an existing _Layout.cshtml, the scaffolder (dotnet aspnet-codegenerator identity) doesn't generate links pointing to the scaffolded assets in the project. Instead, it points to the assets provided by the Microsoft.AspNetCore.Identity.UI package.

Steps to reproduce

1. Create a new ASP.NET Core Web API App (dotnet new webapi)
2. Add the necessary packages to the project:

   dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design
   dotnet add package Microsoft.EntityFrameworkCore.Design
   dotnet add package Microsoft.AspNetCore.Identity.EntityFrameworkCore
   dotnet add package Microsoft.AspNetCore.Identity.UI
   dotnet add package Microsoft.EntityFrameworkCore.SqlServer
   dotnet add package Microsoft.EntityFrameworkCore.Tools
   

3. Run the scaffolder:

   dotnet aspnet-codegenerator identity
   

   NOTE: The --useDefaultUI flag is intentionally excluded here
4. Add the following lines to Program.cs:

   builder.Services.AddRazorPages();
   // ...
   var app = builder.Build();
   // ...
   app.MapStaticAssets();
   app.MapRazorPages()
       .WithStaticAssets();

   💭 Thought: Maybe these changes should be included by the scaffolder as well? 💭
5. Make a trivial edit to one of the scaffolded assets (e.g., add a comment in bootstrap.css)
6. Run the app, and navigate to the /identity/account/login page
7. Look at the sources tab, and notice that the loaded assets don't include the edit made in step 5.

Expected behavior

When not specifying the --useDefaultUI option, the links in _Layout.cshtml should point to scaffolded assets, not assets in the Microsoft.AspNetCore.Identity.UI package.

Actual behavior

Each resource link in _Layout.cshtml has an ~/Identity prefix, which causes the assets to be loaded from Microsoft.AspNetCore.Identity.UI.