retrieve_utils.py - Updated.py to have the ability to parse text from PDF Files (#50)

* UPDATE - Updated retrieve_utils.py to have the ability to parse text from pdf files

* UNDO - change to recursive condition

* UPDATE - updated agentchat_RetrieveChat.ipynb to clarify which file types are accepted to be in the docs path

* ADD - missing import

* UPDATE - setup.py to have PyPDF2 in retrievechat

* RE-ADD - urls

* ADD - tests for retrieve utils, and removed deprecated PyPdf2

* Update agentchat_RetrieveChat.ipynb

* Update retrieve_utils.py

Fix format

* Update retrieve_utils.py

Replace print with logger

* UPDATE - added more specific exception to PDF decryption try/catch

* FIX - typo, return statement at wrong indentation in extract_text_from_pdf

---------

Co-authored-by: Ward <award40@LAMU0CLP74YXVX6.uhc.com>
Co-authored-by: Li Jiang <bnujli@gmail.com>