Make multiple arity option overflow behavior consistent with argument behavior

This currently works:

```csharp
var intsArg = new Argument();
var stringsArg = new Argument();

var root = new RootCommand
{
intsArg,
stringsArg
};

var result = root.Parse("1 2 3 four five");

var _ = new AssertionScope();

result.ValueForArgument(intsArg)
.Should()
.BeEquivalentTo(new[] { 1, 2, 3 },
options => options.WithStrictOrdering());

result.ValueForArgument(stringsArg)
.Should()
.Be("four");

result.UnparsedTokens.Should()
.ContainSingle()
.Which
.Should()
.Be("five");
```

This (with the change of `intArg` to `intsOption`) does not:

```csharp
var intsOption = new Option("-i");
var stringsArg = new Argument("arg");

var root = new RootCommand
{
intsOption,
stringsArg
};

var result = root.Parse("-i 1 2 3 four");

result.FindResultFor(intsOption)
.GetValueOrDefault()
.Should()
.BeEquivalentTo(new[] { 1, 2, 3 }, options => options.WithStrictOrdering());

result.FindResultFor(stringsArg)
.Should()
.Be("four");
```

It seems these should be consistent, although the fact that arguments are positional and options are not might make this unintuitive.