Multi instance setting ignored when default verb is parsed.

Comece reproduzindo o problema com o exemplo fornecido de ParseArguments e MapResult, especialmente argTest5, e rastreie como o verbo padrão é analisado com AllowMultiInstance habilitado. O trabalho estará concluído quando o verbo padrão aceitar valores de opção repetidos sem informar que a opção foi definida várias vezes, enquanto os outros exemplos continuarem sendo analisados corretamente.

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<string> OptionA { get; set; }

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

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

        [Option('e', HelpText = "Option E for save command")]
        public IEnumerable<string> 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<LogOptions, SaveOptions>(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.