Server-side Blazor template cleanups for Preview 4 (#9025)

* Rename Host.cshtml to _Host.cshtml

* In Startup.cs, specify root component and selector explicitly so you can easily disable prerendering if desired

* Remove unneccesary dependency on NewtonsoftJson package

* Remove unnecessary MapRazorPages and make blank lines consistent

* Rename "Services" subdirectory to "Data"

* Remove favicon.ico (no longer needed since we switched to MapFallbackToPage

* Revert MapComponentHub change due to reasons

src/ProjectTemplates/Web.ProjectTemplates/RazorComponentsWeb-CSharp.csproj.in

@@ -10,7 +10,6 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Components.Prerendering" Version="${MicrosoftAspNetCoreMvcComponentsPrerenderingPackageVersion}" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="${MicrosoftAspNetCoreMvcNewtonsoftJsonPackageVersion}" />
   </ItemGroup>
 
 </Project>

src/ProjectTemplates/Web.ProjectTemplates/content/RazorComponentsWeb-CSharp/Data/WeatherForecast.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace RazorComponentsWeb_CSharp.Services
+namespace RazorComponentsWeb_CSharp.Data
 {
     public class WeatherForecast
     {

src/ProjectTemplates/Web.ProjectTemplates/content/RazorComponentsWeb-CSharp/Data/WeatherForecastService.cs

@@ -2,7 +2,7 @@ using System;
 using System.Linq;
 using System.Threading.Tasks;
 
-namespace RazorComponentsWeb_CSharp.Services
+namespace RazorComponentsWeb_CSharp.Data
 {
     public class WeatherForecastService
     {

src/ProjectTemplates/Web.ProjectTemplates/content/RazorComponentsWeb-CSharp/Pages/FetchData.razor

@@ -1,5 +1,5 @@
 @page "/fetchdata"
-@using RazorComponentsWeb_CSharp.Services
+@using RazorComponentsWeb_CSharp.Data
 @inject WeatherForecastService ForecastService
 
 <h1>Weather forecast</h1>

src/ProjectTemplates/Web.ProjectTemplates/content/RazorComponentsWeb-CSharp/Startup.cs

@@ -10,7 +10,7 @@ using Microsoft.AspNetCore.HttpsPolicy;
 #endif
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
-using RazorComponentsWeb_CSharp.Services;
+using RazorComponentsWeb_CSharp.Data;
 
 namespace RazorComponentsWeb_CSharp
 {
@@ -20,11 +20,8 @@ namespace RazorComponentsWeb_CSharp
         // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
         public void ConfigureServices(IServiceCollection services)
         {
-            services.AddRazorPages()
+            services.AddRazorPages();
-                .AddNewtonsoftJson();
-
             services.AddRazorComponents();
-
             services.AddSingleton<WeatherForecastService>();
         }
 
@@ -45,6 +42,7 @@ namespace RazorComponentsWeb_CSharp
 
 #if (RequiresHttps)
             app.UseHttpsRedirection();
+
 #endif
             app.UseStaticFiles();
 
@@ -52,9 +50,8 @@ namespace RazorComponentsWeb_CSharp
 
             app.UseEndpoints(endpoints =>
             {
-                endpoints.MapRazorPages();
                 endpoints.MapComponentHub();
-                endpoints.MapFallbackToPage("/Host");
+                endpoints.MapFallbackToPage("/_Host");
             });
         }
     }