Add logging message with number of patients notified to Einstein

@katie.kalt Added a logging message that displays the number of patients processed and the message returned from the /Notify_Einstein endpoint. Another way to check the number of patients processed is to check the /Get_status endpoint which already displays the number of processed patients. Example:

[2024-09-26, 08:34:48 CEST] {logging_mixin.py:190} INFO - Connector notified 2 patients successfully to Einstein. Response returned from Einstein endpoint: "Patients data notified to Einstein successfully"