Split Area for pages

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

Many systems like mine have Areas.
Let's assume that in my case it looks like this:
- Web, this is an area available to anyone
- Manage, this is the area available to the logged in person
- Management, this is an area available only to administration.

This is how my plugin tree looks like:
```
├───Areas
│ ├───Manage
│ │ │ _Imports.razor
│ │ │
│ │ └───Pages
│ │ Edit.razor
│ │ Edit.razor.cs
│ │ List.razor
│ │ List.razor.cs
│ │
│ ├───Management
│ │ │ _Imports.razor
│ │ │
│ │ └───Pages
│ │ Draft.razor
│ │ Draft.razor.cs
│ │ Edit.razor
│ │ Edit.razor.cs
│ │ List.razor
│ │ List.razor.cs
│ │
│ └───Web
│ │ _Imports.razor
│ │
│ ├───Pages
│ │ Article.razor
│ │ Article.razor.cs
│ │ Articles.razor
│ │ Articles.razor.cs
│ │ Search.razor
│ │ Search.razor.cs
│ │
│ └───Shared
│ ArticleCardCaption.razor
│ ArticleHead.razor
│ ArticlePopular.razor
```

You used to be able to separate everything into arenas that were separated, they could have their ``App.razor`` and ``Routing.razor``.
Now it's all lumped into one ``bag''.

```
endpoints.MapRazorComponents()
.AddInteractiveServerRenderMode()
.AddInteractiveWebAssemblyRenderMode()
.AddAdditionalAssemblies(assemblyWeb);

endpoints.MapRazorComponents()
.AddInteractiveServerRenderMode()
.AddInteractiveWebAssemblyRenderMode()
.AddAdditionalAssemblies(assemblyManager);

endpoints.MapRazorComponents()
.AddInteractiveServerRenderMode()
.AddInteractiveWebAssemblyRenderMode()
.AddAdditionalAssemblies(assemblyManagement);
```

It is now possible to solve this problem but only by creating a solucja (we are coming up with three more solucja). I think this is a bad solution and we need to have an impact on which pages should appear in routing.

If we add a component in ``AdditionalAssemblies`` it finds all other components from a given soluition. Instead of taking the Assmelby parameter, you can change it to Type[], then we can indicate the exact location of the component in question

### Describe the solution you'd like

I would like it to be possible to indicate exactly the components to be under a given routing. He wants to separate everything. Each area has different values.

### Additional context

_No response_