Add support for WebRTC-Direct transport in MultiAddress

[Arlodotexe]

Add support for WebRTC-Direct transport in NetworkProtocol.

• Add a new class WebRtcDirectNetworkProtocol to handle WebRTC-Direct protocol.
• Register the new class in the static constructor of NetworkProtocol.

[Arlodotexe]

Tested locally in OwlCore.Kubo, was able to validate that this change fixes the issue with the latest Kubo 0.32.1.