feat: create loading widget

lib/src/providers/auth_provider.dart

@@ -74,10 +74,10 @@ class AuthProvider with ChangeNotifier {
   }
 
   Future<void> signOut() async {
-    isLoading = true;
     final token = await getAccessToken();
 
     try {
+      setLoading(true);
       final response = await http.get(
         Uri.parse('$baseUrl/auth/logout'),
         headers: {
@@ -94,7 +94,7 @@ class AuthProvider with ChangeNotifier {
         debugPrint("Logout failed: ${response.statusCode} ${response.body}");
       }
 
-      isLoading = false;
+      setLoading(false);
       notifyListeners();
     } catch (error) {
       debugPrint("Logout failed $error");

lib/src/widgets/forms/login_form.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_svg/flutter_svg.dart';
 import 'package:library_app/src/providers/auth_provider.dart';
 import 'package:library_app/src/screens/form_screen.dart';
+import 'package:library_app/src/widgets/loading.dart';
 import 'package:provider/provider.dart';
 
 class LoginForm extends StatefulWidget {
@@ -134,14 +135,7 @@ class _LoginForm extends State<LoginForm> {
                             );
                           },
                           child: authProvider.isLoading
-                              ? const SizedBox(
-                                  width: 20.0,
-                                  height: 20.0,
-                                  child: CircularProgressIndicator(
-                                    color: Colors.white,
-                                    strokeWidth: 3.0,
-                                  ),
-                                )
+                              ? const Loading()
                               : const Text("Submit"),
                         ),
                       ),

lib/src/widgets/loading.dart

+import 'package:flutter/material.dart';
+
+class Loading extends StatelessWidget {
+  const Loading({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return const SizedBox(
+      width: 20.0,
+      height: 20.0,
+      child: CircularProgressIndicator(
+        color: Colors.white,
+        strokeWidth: 3.0,
+      ),
+    );
+  }
+}