Windows 10+ / WebAuthn client API for .NET using P/Invoke

• Yoq.WindowsWebAuthn.Pinvoke: Marshaling library to make the Win 10 WebAuthn API available on .NET 4+
• Yoq.WindowsWebAuthn.Managed: Directly send/receive Fido2.Models objects to the authenticator using the P/Invoke library. Available on .NET6+
• Yoq.WindowsWebAuthn.Demo: A CLI demo application