fix #2513 - add new methods for deleting a setting and retrieving a list of settings

Oqtane.Client/Services/Interfaces/ISettingService.cs

@@ -164,6 +164,24 @@ namespace Oqtane.Services
         /// <returns></returns>
         Task UpdateSettingsAsync(Dictionary<string, string> settings, string entityName, int entityId);
 
+        /// <summary>
+        /// Returns a specific setting
+        /// </summary>
+        /// <param name="entityName"></param>
+        /// <param name="entityId"></param>
+        /// <param name="settingName"></param>
+        /// <returns></returns>
+        Task DeleteSettingAsync(string entityName, int entityId, string settingName);
+
+        /// <summary>
+        /// Returns a specific setting
+        /// </summary>
+        /// <param name="entityName"></param>
+        /// <param name="entityId"></param>
+        /// <param name="settingName"></param>
+        /// <returns></returns>
+        Task<List<Setting>> GetSettingsAsync(string entityName, int entityId, string settingName);
+
         /// <summary>
         /// Returns a specific setting
         /// </summary>