TF-2517 Fix rename/create a folder with special characters do not show error message

lib/features/mailbox_creator/domain/extensions/mailbox_name_special_character_validator_extension.dart

@@ -0,0 +1,15 @@
+
+extension MailboxNameSpecialCharacterValidatorExtension on String {
+  bool get isValid {
+    if (startsWith('#')) {
+      return false;
+    }
+
+    final forbiddenChars = RegExp(r'[%*\r\n]');
+    if (forbiddenChars.hasMatch(this)) {
+      return false;
+    }
+
+    return true;
+  }
+}

lib/features/mailbox_creator/domain/extensions/name_validator_string_extension.dart

@@ -1,6 +0,0 @@
-
-extension NameValidatorStringExtension on String {
-  bool hasSpecialCharactersInName() {
-    return  RegExp(r'(?=.*?[#?!@$%^&*)(=+}{:;?/|\\><.,`~])').hasMatch(this);
-  }
-}