Add language repository & controller

Oqtane.Server/Repository/Interfaces/ILanguageRepository.cs

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+using Oqtane.Models;
+
+namespace Oqtane.Repository
+{
+    public interface ILanguageRepository
+    {
+        IEnumerable<Language> GetLanguages(int siteId);
+
+        Language AddLanguage(Language language);
+
+        Language GetLanguage(int languageId);
+
+        void DeleteLanguage(int languageId);
+    }
+}