Multi instance setting ignored when default verb is parsed.

**Describe the bug**
When using the function "MapResult" to parse multiple verbs, the parser ignores the setting "AllowMultiInstance" while parsing the default verb.

Lib version: 2.9.1
Language: C#

**To Reproduce**
Test the following demo code to see the result.

Demo Class Options:
```
[Verb("log", isDefault:true, HelpText = "Log command")]
class LogOptions
{
[Option('a', HelpText = "Option A for log command")]
public IEnumerable OptionA { get; set; }

[Option('b', HelpText = "Option B for log command")]
public IEnumerable OptionB { get; set; }
}

[Verb("save", HelpText = "Save command")]
class SaveOptions
{
[Option('d', HelpText = "Option D for save command")]
public IEnumerable OptionD { get; set; }

[Option('e', HelpText = "Option E for save command")]
public IEnumerable OptionE { get; set; }
}
```
Demo code:
```
Parser parser = new(x =>
{
x.HelpWriter = Console.Out;
x.IgnoreUnknownArguments = true;
x.AllowMultiInstance = true;
x.AutoHelp = true;
});

var argTest1 = "log -a valueA -b valueB" .Split(' '); // This works.
var argTest2 = "save -d valueD -e valueE".Split(' '); // This works.
var argTest3 = "-a valueA -b valueB".Split(' '); // This works.
var argTest4 = "log -a valueA -b valueB -b valueB2".Split(' '); // This works.
var argTest5 = " -a valueA -b valueB -b valueB2".Split(' '); // This don't work.

var res = parser.ParseArguments(argTest5).MapResult(
(LogOptions opts) => ProcessLogCommand(opts),
(SaveOptions opts) => ProcessSaveCommand(opts),
errs => 1);
}
```

When trying to parse argTest5 this error is shown:

```
ERROR(S):
Option 'b' is defined multiple times.

-a Option A for log command

-b Option B for log command

--help Display this help screen.

--version Display version information.
```

**Expected behavior**
Option "SaveOptions" correctly parsed with multiple arguments for argument b.

Empieza reproduciendo el problema con el ejemplo proporcionado de ParseArguments y MapResult, especialmente argTest5, y sigue cómo se analiza el verbo predeterminado con AllowMultiInstance habilitado. Se considera terminado cuando el verbo predeterminado acepta valores de opción repetidos sin informar de que la opción está definida varias veces, mientras los demás ejemplos siguen analizándose correctamente.

Escrito por el modelo de indexación a partir del texto del issue.