TF-528 Apply linter for some widget

lib/features/mailbox_creator/domain/exceptions/verify_name_exception.dart

@@ -2,31 +2,31 @@
 import 'package:equatable/equatable.dart';
 
 abstract class VerifyNameException extends Equatable implements Exception {
-  static const EmptyName = 'The name cannot be empty!';
-  static const DuplicatedName = 'The name already exists!';
-  static const NameContainSpecialCharacter = 'The name cannot contain special characters';
+  static const emptyName = 'The name cannot be empty!';
+  static const duplicatedName = 'The name already exists!';
+  static const nameContainSpecialCharacter = 'The name cannot contain special characters';
 
   final String? message;
 
-  VerifyNameException(this.message);
+  const VerifyNameException(this.message);
 }
 
 class EmptyNameException extends VerifyNameException {
-  EmptyNameException() : super(VerifyNameException.EmptyName);
+  const EmptyNameException() : super(VerifyNameException.emptyName);
 
   @override
   List<Object> get props => [];
 }
 
 class DuplicatedNameException extends VerifyNameException {
-  DuplicatedNameException() : super(VerifyNameException.DuplicatedName);
+  const DuplicatedNameException() : super(VerifyNameException.duplicatedName);
 
   @override
   List<Object> get props => [];
 }
 
 class SpecialCharacterException extends VerifyNameException {
-  SpecialCharacterException() : super(VerifyNameException.NameContainSpecialCharacter);
+  const SpecialCharacterException() : super(VerifyNameException.nameContainSpecialCharacter);
 
   @override
   List<Object> get props => [];

lib/features/mailbox_creator/domain/model/verification/duplicate_name_validator.dart

@@ -17,7 +17,7 @@ class DuplicateNameValidator extends Validator<NewNameRequest> {
           .map((nameItem) => nameItem.toLowerCase())
           .contains(newNameRequest.value!.toLowerCase());
       if (nameExist) {
-        return Left<Failure, Success>(VerifyNameFailure(DuplicatedNameException()));
+        return Left<Failure, Success>(VerifyNameFailure(const DuplicatedNameException()));
       } else {
         return Right<Failure, Success>(VerifyNameViewState());
       }

lib/features/mailbox_creator/domain/model/verification/empty_name_validator.dart

@@ -11,7 +11,7 @@ class EmptyNameValidator extends Validator<NewNameRequest> {
   @override
   Either<Failure, Success> validate(NewNameRequest newNameRequest) {
     if (newNameRequest.value == null || newNameRequest.value!.isEmpty) {
-      return Left<Failure, Success>(VerifyNameFailure(EmptyNameException()));
+      return Left<Failure, Success>(VerifyNameFailure(const EmptyNameException()));
     } else {
       return Right<Failure, Success>(VerifyNameViewState());
     }

lib/features/mailbox_creator/domain/model/verification/special_character_validator.dart

@@ -12,7 +12,7 @@ class SpecialCharacterValidator extends Validator<NewNameRequest> {
   @override
   Either<Failure, Success> validate(NewNameRequest newNameRequest) {
     if (newNameRequest.value != null && newNameRequest.value!.hasSpecialCharactersInName()) {
-      return Left<Failure, Success>(VerifyNameFailure(SpecialCharacterException()));
+      return Left<Failure, Success>(VerifyNameFailure(const SpecialCharacterException()));
     } else {
       return Right<Failure, Success>(VerifyNameViewState());
     }