Add an optional telemetry component

[arthuraraujo-msft]

Add an optional telemetry component to the library.
One idea is to allow users to set a telemetry callback class that implements an interface. This interface will be invoked with the telemetry data at certain points of the flow, and the user will handle the telemetry appropriately.
We can also provide an example implementation using some kind of library.

The interface could be something like:

class TelemetryInterface
{
   virtual void HTTPRequestSucceeded(const std::string& timeStamp, const std::string& correlationVector, const std::string& url) = 0;
   virtual void HTTPRequestFailed(const std::string& timeStamp, const std::string& correlationVector, const std::string& url) = 0;
   virtual void UnexpectedError(const std::string& message) = 0;
};