introduce ITransientService interface for auto registration of transient services (for DBContexts and Repositories)

Oqtane.Shared/Interfaces/ITransientService.cs

@@ -0,0 +1,9 @@
+namespace Oqtane.Modules
+{
+    /// <summary>
+    /// Empty interface used to decorate module services for auto registration as a transient
+    /// </summary>
+    public interface ITransientService
+    {
+    }
+}