Factor out default controller route.

Oqtane.Server/Controllers/ModuleDefinitionController.cs

@@ -19,7 +19,7 @@ using System.Text.Json;
 
 namespace Oqtane.Controllers
 {
-    [Route("{alias}/api/[controller]")]
+    [Route(ControllerRoutes.Default)]
     public class ModuleDefinitionController : Controller
     {
         private readonly IModuleDefinitionRepository _moduleDefinitions;