fix incorrect default naming in the template code (not in the book)

Author: ssg

CH03/Shoppidy/Controllers/HomeController.cs

@@ -11,11 +11,11 @@ namespace Shoppidy.Controllers
 {
     public class HomeController : Controller
     {
-        private readonly ILogger<HomeController> _logger;
+        private readonly ILogger<HomeController> logger;
 
         public HomeController(ILogger<HomeController> logger)
         {
-            _logger = logger;
+            this.logger = logger;
         }
 
         public IActionResult Index()

CH03/Twistat/Pages/Error.cshtml.cs

@@ -12,11 +12,11 @@ public class ErrorModel : PageModel
 
         public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);
 
-        private readonly ILogger<ErrorModel> _logger;
+        private readonly ILogger<ErrorModel> logger;
 
         public ErrorModel(ILogger<ErrorModel> logger)
         {
-            _logger = logger;
+            this.logger = logger;
         }
 
         public void OnGet()

CH03/Twistat/Pages/Index.cshtml.cs

@@ -5,11 +5,11 @@ namespace Twistat.Pages
 {
     public class IndexModel : PageModel
     {
-        private readonly ILogger<IndexModel> _logger;
+        private readonly ILogger<IndexModel> logger;
 
         public IndexModel(ILogger<IndexModel> logger)
         {
-            _logger = logger;
+            this.logger = logger;
         }
 
         public void OnGet()

CH03/Twistat/Pages/Privacy.cshtml.cs

@@ -5,11 +5,11 @@ namespace Twistat.Pages
 {
     public class PrivacyModel : PageModel
     {
-        private readonly ILogger<PrivacyModel> _logger;
+        private readonly ILogger<PrivacyModel> logger;
 
         public PrivacyModel(ILogger<PrivacyModel> logger)
         {
-            _logger = logger;
+            this.logger = logger;
         }
 
         public void OnGet()