added option to make deferred evaluation quieter

[epinzur]

Items to add to release announcement:

• Added Option to make deferred evaluation quieter:
  • If using Deferred evaluation mode with the tru.start_evaluator() method, there is a new disable_tqdm flag (default False), that disables the tqdm progress bars written to stdout when set True.
  • This is useful when you are managing the evaluation progress via some other method.

Other details that are good to know but need not be announced:

• This also disables:
  • the nltk.download() logging that appears very often in the deferred evaluation log output.
  • the progress bars from the groundedness_measure_with_cot_reasons feedback function.
    • Note: I wanted to make a flag to also optionally disable these progress bars, but I was un-successful in doing so.