LiteNetLib 2.0.2

This is mostly api updates

• Move one of channeled Send method from LiteNetPeer to NetPeer
• Move channeled SendToAll from LiteNetManager to NetManager
• Add "new" NetPeer FirstPeer property to NetManager
• Also add IEnumerable<NetPeer> to NetManager

Full Changelog: 2.0.0...2.0.2