Add missing websocket functions

[ptesavol]

• Make the libdatachannel WebSocket support complete by adding the previously-missing functions to the WebSocket class:

     forceClose(): void;
     remoteAddress(): string | undefined;
     path(): string | undefined; 

• Add missing open(string: url) function to the typescript typings of WebSocket
• Replace 'libWebSocket' -> 'libdatachannel' in debug logging

[murat-dogan]

Thanks

[murat-dogan]

Should we call also doCleanup function? I don't know if close event is triggered also on forceClose process.
If not we need to call it.