FriendlyFlags.Array should generate Span<T> overloads

Given a method with such a parameter:

```cs
[Friendly(FriendlyFlags.Out | FriendlyFlags.Array)] char* lpString,
```

We should produce an overload with parameter type `Span<char>`.

Also if the direction is only `In`:

```cs
[Friendly(FriendlyFlags.In | FriendlyFlags.Array)] char* lpString,
```

We should produce an overload with parameter type `ReadOnlySpan<char>`.