Add 🦖 RexHaqs code for redirect to authorized endpoint of app

[guardrex]

We're going to toss up my 🦖 RexHaqs™ 🙈 for the the location change that would redirect back to a secure endpoint, which just throws the user back into sign in.

[guardrex]

This was dealt with in the article on dotnet/AspNetCore.Docs#31841.

[guardrex]

I'm going to leave my hacks on here for reference ...

var currentUrl = NavigationManager.ToBaseRelativePath(e.Location);

var matchingAuthComponentCount = System.Reflection.Assembly.GetExecutingAssembly()
    .ExportedTypes
    .Where(t => t.IsSubclassOf(typeof(ComponentBase)))
    .Where(c => c.GetCustomAttributes(inherit: true)
            .OfType<AuthorizeAttribute>()
            .ToArray()
            .Count() > 0 &&
            c.GetCustomAttributes(inherit: true)
            .OfType<RouteAttribute>()
            .Where(d => d.Template == $"/{currentUrl}")
            .Count() > 0)
    .Count();

if (matchingAuthComponentCount > 0)
{
    currentUrl = NavigationManager.BaseUri;
}

Noting Stephen's remark that another way that only works server-side is ...

var endpoint = httpContext.GetEndpoint();
// [Authorize] implements IAuthorizeData
var requiresAuthorization = endpoint?.Metadata.GetMetadata<IAuthorizeData>() is not null;