[Blazor] Rewrite AddServerSideBlazor as a wrapper around AddRazorComponents

[javiercn]

• Customers should use services.AddRazorComponents().AddServerComponents() instead.
• At the very least, we should make the implementation of AddServerSideBlazor go through AddRazorComponents internally.

[SteveSandersonMS]

TBH I'd side with

At the very least, we should make the implementation of AddServerSideBlazor go through AddRazorComponents internally.

... and not obsolete AddServerSideBlazor for .NET 8. That's because we don't yet know for sure the new code paths will work for everyone.

[surayya-MS]

@javiercn , @SteveSandersonMS do we need to call MapRazorComponents wherever AddServerSideBlazor (services.AddRazorComponents().AddServerComponents()) was used?

[surayya-MS]

Also what is the reason for calling services.AddRazorComponents().AddServerComponents() in AddServerSideBlazor?
Currently AddServerComponents calls AddServerSideBlazor https://github.com/dotnet/aspnetcore/blob/main/src/Components/Server/src/DependencyInjection/RazorComponentsBuilderExtensions.cs#L32
Why we need extra stuff from AddRazorComponents?