Adding implementation for generating AAD access tokens for azure integration tests
This PR is dealing with implementation for generating AAD access tokens for integration tests in unit_test_azure. The changes are made to jwt_client.py file which contained two unimplemented methods namely get_id_token and get_invalid_token.
Using MSAL Library for generating the access tokens Relevant changes made to readme.md and requirements.txt file for python packages
Edited by Chad Leong