Minor fix (#579)

* Refactor 404 error handling in CommonController
* Update ContactController

Author: KrzysztofPajak

src/Web/Grand.Web/Controllers/CommonController.cs

@@ -152,7 +152,7 @@ public virtual async Task<IActionResult> SetLanguage(
     {
         var language = await _languageService.GetLanguageByCode(langCode);
         if (language == null)
-            return InvokeHttp404();
+            return NotFound();
 
         if (!language.Published)
             language = _contextAccessor.WorkContext.WorkingLanguage;

src/Web/Grand.Web/Controllers/ContactController.cs

@@ -15,6 +15,7 @@
 using Grand.Web.Events;
 using Grand.Web.Models.Contact;
 using MediatR;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 
 namespace Grand.Web.Controllers;
@@ -39,7 +40,7 @@ public ContactController(
     //available even when a store is closed
     [ClosedStore(true)]
     [HttpGet]
-    public virtual async Task<ActionResult<ContactUsModel>> Index(
+    public virtual async Task<IActionResult> Index(
         [FromServices] StoreInformationSettings storeInformationSettings,
         [FromServices] IPageService pageService)
     {
@@ -62,7 +63,7 @@ public virtual async Task<ActionResult<ContactUsModel>> Index(
     [AutoValidateAntiforgeryToken]
     [ClosedStore(true)]
     [DenySystemAccount]
-    public virtual async Task<ActionResult<ContactUsModel>> Index(
+    public virtual async Task<IActionResult> Index(
         [FromServices] StoreInformationSettings storeInformationSettings,
         [FromServices] IPageService pageService,
         ContactUsModel model)