Added ability to install modules and skins at run-time directly from Nuget

Oqtane.Client/Services/Interfaces/IPackageService.cs

@@ -0,0 +1,12 @@
+using Oqtane.Models;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace Oqtane.Services
+{
+    public interface IPackageService
+    {
+        Task<List<Package>> GetPackagesAsync(string Tag);
+        Task DownloadPackageAsync(string PackageId, string Version, string Folder);
+    }
+}