search refactoring

Oqtane.Shared/Interfaces/ISearchable.cs

@@ -1,11 +1,12 @@
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Oqtane.Models;
 
 namespace Oqtane.Interfaces
 {
     public interface ISearchable
     {
-        public List<SearchContent> GetSearchContents(PageModule pageModule, DateTime startTime);
+        public Task<List<SearchContent>> GetSearchContentsAsync(PageModule pageModule, DateTime lastIndexedOn);
     }
 }