Fix #4936: add the cookie consent theme control.

Oqtane.Client/Services/Interfaces/ICookieConsentService.cs

@@ -0,0 +1,24 @@
+using Oqtane.Models;
+using System;
+using System.Threading.Tasks;
+
+namespace Oqtane.Services
+{
+    /// <summary>
+    /// Service to retrieve cookie consent information.
+    /// </summary>
+    public interface ICookieConsentService
+    {
+        /// <summary>
+        /// Get cookie consent status
+        /// </summary>
+        /// <returns></returns>
+        Task<bool> CanTrackAsync();
+
+        /// <summary>
+        /// Grant cookie consent
+        /// </summary>
+        /// <returns></returns>
+        Task<string> CreateConsentCookieAsync();
+    }
+}