Convert window/showMessage notifications to telemetry/event

[fm-117]

Child of #2668.

This is a minimalistic approach to LS exception tracking :

• in TypeCobolServerHost, as soon as the TypeCobolServer instance is available , add a new ILogger.
  • this new logger would be responsible for sending a telemetry/event as described in #2668 when the LogException method is called. It will be naturally dependent from the TypeCobolServer as it requires to send JSON to the client.
• remove the call to ShowErrorMessage from NotifyException and move it to UnhandledExceptionHandler, to ensure a message is still displayed in the event of a server crash.