[FormBuilderValidators.maxLength & .minLength]: If the value to be verified is not a String but an Iterable, errorText is incorrect.

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Package/Plugin version

9.1.0

### Platforms

- [ ] Android
- [ ] iOS
- [ ] Linux
- [ ] MacOS
- [ ] Web
- [X] Windows

### Flutter doctor

Flutter doctor

```bash
[√] Flutter (Channel stable, 3.19.4, on Microsoft Windows [Version 10.0.22631.3296], locale ja-JP)
• Flutter version 3.19.4 on channel stable at C:\src\flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 68bfaea224 (2 weeks ago), 2024-03-20 15:36:31 -0700
• Engine revision a5c24f538d
• Dart version 3.3.2
• DevTools version 2.31.1

[√] Windows Version (Installed version of Windows is version 10 or higher)

[√] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
• Android SDK at C:\Users\sugur\AppData\Local\Android\sdk
• Platform android-34, build-tools 34.0.0
• Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java
• Java version OpenJDK Runtime Environment (build 17.0.9+0--11185874)
• All Android licenses accepted.

[√] Chrome - develop for the web
• Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.9.4)
• Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
• Visual Studio Community 2022 version 17.9.34714.143
• Windows 10 SDK version 10.0.22000.0

[√] Android Studio (version 2023.3)
• Android Studio at C:\Program Files\Android\Android Studio
• Flutter plugin can be installed from:
https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 17.0.9+0--11185874)

[√] VS Code (version 1.87.2)
• VS Code at C:\Users\sugur\AppData\Local\Programs\Microsoft VS Code
• Flutter extension can be installed from:
https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[√] Connected device (3 available)
• Windows (desktop) • windows • windows-x64 • Microsoft Windows [Version 10.0.22631.3296]
• Chrome (web) • chrome • web-javascript • Google Chrome 123.0.6312.86
• Edge (web) • edge • web-javascript • Microsoft Edge 123.0.2420.65

[√] Network resources
• All expected network resources are available.

• No issues found!
```

### Minimal code example

Code sample

I omitted the part where the language of the application is set to another language (Japanese) because it is not essential.

```dart
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key});

@override
State createState() => _MyHomePageState();
}

class _MyHomePageState extends State {
final mediaList = ['test1', 'test2', 'test3'];

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
title: const Text('AppBar'),
),
body: Center(
child: FormBuilderList(mediaList: mediaList),
),
);
}
}

class FormBuilderList extends StatelessWidget {
const FormBuilderList({
super.key,
required this.mediaList,
});

final List mediaList;

@override
Widget build(BuildContext context) {
return FormBuilderField>(
name: 'name',
validator: FormBuilderValidators.compose([
FormBuilderValidators.maxLength(2),
// FormBuilderValidators.minLength(4),
]),
autovalidateMode: AutovalidateMode.always,
builder: (field) {
return InputDecorator(
decoration: InputDecoration(
border: InputBorder.none,
errorText: field.errorText,
),
child: SizedBox(
height: 100,
child: ListView.separated(
scrollDirection: Axis.horizontal,
itemCount: mediaList.length,
itemBuilder: (context, index) {
final media = mediaList[index];
return InkWell(
onTap: () {
// call validate
field.didChange([...mediaList]);
},
child: SizedBox(
width: 100,
height: 100,
child: Image.file(File(media), key: ValueKey(index))),
);
},
separatorBuilder: (context, index) => const SizedBox.shrink(),
),
),
);
},
);
}
}
```

### Current Behavior

The string displayed during Validate is "$maxLength文字以下で入力してください。" / "$maxLength文字以上で入力してください。"

### Expected Behavior

This statement is only valid if the element is a String.

If it is not a String but an Iterable, the errorText should be as follows.

"$maxLength個以下にしてください。" / "$maxLength個以上にしてください。"

### Steps To Reproduce

1. Run the application with the Minimal code example and the code with the Japanese language setting process added.

2. Tap the image widget.

### Aditional information

Prepare a message in the case of Iterable to each language.

https://github.com/flutter-form-builder-ecosystem/form_builder_validators/blob/9.1.0/lib/localization/intl/messages_ja.dart

Then, the errorText acquisition part should be branched to String / Iterable to ensure correct processing.

https://github.com/flutter-form-builder-ecosystem/form_builder_validators/blob/1fea11258a1fc82b9e137e3bc6492f1272aba023/lib/src/form_builder_validators.dart#L128-L147