Code adaptation

[tinohager]

Would you accept a pull request with which I bring more structure to the project?

• I would rename the private variables to _clientWebSocket instead of private ClientWebSocket WebSocket.
• I would add an ILogger
• I would integrate CancellationTokens
• I would change the method names to StartAsync.

That would of course be a breaking change...

[akacdev]

Since I initially released this library over two years ago, I’m sure the code could benefit from the best practices you've suggested. Feel free to proceed with those cosmetic changes and I'll be happy to merge them in.

[tinohager]

@akacdev You are now welcome to take a look at my changes and try out the new version for yourself

[akacdev]

There is a minor issue where the fire-and-forget method call in StartAsync swallows the potential CertstreamException from the message receiving loop.