Processes a generic timestamp request.
This method processes a generic timestamping request and produces a response. Use it to generate timestamps for requests obtained externally, out of the default HTTP channel.
This method respects all current settings of the server object, and invokes TimestampRequest to consult about the request and response details with the application.
If TimeTokenOnly is set, the return value will only contain the TimeStampToken piece of the response. If it is switched off, the whole TimeStampResp structure will be returned.