v9 Update: First MVC Series: Version Prep Only

[wadepickett]

Contributes to #32708

This is only the version prep to get ready for the actual update:

v8.0 of the app samples were copied to a v9.0 version and the code snippets linked over to those.
Version 8 of each topic was moved to an include.

These files are copied over during this prep PR, so that changes actually made for the new version for .NET 9 will be easily seen in the difference and easier to review.

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Internal previews

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📄 File	🔗 Preview link
aspnetcore/tutorials/first-mvc-app/adding-controller.md	Part 2, add a controller to an ASP.NET Core MVC app
aspnetcore/tutorials/first-mvc-app/adding-model.md	[Visual Studio](https://review.learn.microsoft.com/en-us/aspnet/core/tutorials/first-mvc-app/adding-model?branch=pr-en-us-33150)
aspnetcore/tutorials/first-mvc-app/adding-view.md	[Visual Studio](https://review.learn.microsoft.com/en-us/aspnet/core/tutorials/first-mvc-app/adding-view?branch=pr-en-us-33150)
aspnetcore/tutorials/first-mvc-app/controller-methods-views.md	Part 6, controller methods and views in ASP.NET Core
aspnetcore/tutorials/first-mvc-app/details.md	Part 10, examine the Details and Delete methods of an ASP.NET Core app
aspnetcore/tutorials/first-mvc-app/new-field.md	[Visual Studio / Visual Studio for Mac](https://review.learn.microsoft.com/en-us/aspnet/core/tutorials/first-mvc-app/new-field?branch=pr-en-us-33150)
aspnetcore/tutorials/first-mvc-app/search.md	aspnetcore/tutorials/first-mvc-app/search
aspnetcore/tutorials/first-mvc-app/start-mvc.md	Get started with ASP.NET Core MVC
aspnetcore/tutorials/first-mvc-app/start-mvc/sample/9.0-completed/wwwroot/lib/jquery-validation/LICENSE.md	aspnetcore/tutorials/first-mvc-app/start-mvc/sample/9.0-completed/wwwroot/lib/jquery-validation/LICENSE
aspnetcore/tutorials/first-mvc-app/validation.md	Part 9, add validation to an ASP.NET Core MVC app
aspnetcore/tutorials/first-mvc-app/working-with-sql.md	Part 5, work with a database in an ASP.NET Core MVC app