added support for url mapping and viitors

Oqtane.Client/Services/Interfaces/IVisitorService.cs

@@ -0,0 +1,21 @@
+using Oqtane.Models;
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace Oqtane.Services
+{
+    /// <summary>
+    /// Service to manage <see cref="Visitor"/>s on a <see cref="Site"/>
+    /// </summary>
+    public interface IVisitorService
+    {
+        /// <summary>
+        /// Get all <see cref="Visitor"/>s of this <see cref="Site"/>.
+        ///
+        /// </summary>
+        /// <param name="siteId">ID-reference of a <see cref="Site"/></param>
+        /// <returns></returns>
+        Task<List<Visitor>> GetVisitorsAsync(int siteId, DateTime fromDate);
+    }
+}