consolidate Service interface and implementation classes

Oqtane.Client/Services/LocalizationCookieService.cs

@@ -5,6 +5,19 @@ using Oqtane.Shared;
 
 namespace Oqtane.Services
 {
+    /// <summary>
+    /// Service to set localization cookie
+    /// </summary>
+    public interface ILocalizationCookieService
+    {
+        /// <summary>
+        /// Set the localization cookie
+        /// </summary>
+        /// <param name="culture"></param>
+        /// <returns></returns>
+        Task SetLocalizationCookieAsync(string culture);
+    }
+
     [PrivateApi("Don't show in the documentation, as everything should use the Interface")]
     public class LocalizationCookieService : ServiceBase, ILocalizationCookieService
     {