Fix URL with culture (#11886)

* Ignore casing when comparing default culture

* Ignore casing in GetAssignedWithCulture

Co-authored-by: Bjarke Berg <mail@bergmania.dk>

src/Umbraco.PublishedCache.NuCache/DomainCacheExtensions.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Linq;
 using Umbraco.Cms.Core.PublishedCache;
 
@@ -9,7 +10,8 @@ namespace Umbraco.Cms.Infrastructure.PublishedCache
         {
             var assigned = domainCache.GetAssigned(documentId, includeWildcards);
 
-            return culture is null ? assigned.Any() : assigned.Any(x => x.Culture == culture);
+            // It's super important that we always compare cultures with ignore case, since we can't be sure of the casing!
+            return culture is null ? assigned.Any() : assigned.Any(x => x.Culture.Equals(culture, StringComparison.InvariantCultureIgnoreCase));
         }
     }
 }