Improvements

• #6251: Kafka Producer connection now remains active across sends. Added support for group and client id.
  The Kafka producer also adds support for the PLAINTEXT and SASL_SSL protocols.

  DynamoDB table exists check fixed bug when more than 100 tables exist.

• #6814: Replace use of python-telegram-bot package with pyTelegramBotAPI

• #7423: Use response selector keys (sub-intents) as labels for plotting the confusion matrix during NLU evaluation to improve readability.