Security addition - Optionally Separate the username and password from main library

[shijocj1978]

Currently, other than using the username and password to login directly from library, there is no way to inject the authenticated token directly and then save it in pickle file. every time user uses the API they need to pass username, password and 2FA info through wires since they have no idea it is expired.

I wrote a separate standalone Azure function which calls the the login function and returns the token format which is same as pickle file. (includes device_token). This will be used by application to inject the token and then save token into the pickle locally.

Benefit of this approach is to have an additional layer of security where my mobile app or service server will not have to store /pass the username and password and 2FA auth info and will not be compromised incase of a security event. I call my azure function with a RSA token and then get the authenticated token back which will be pushed into library.

I have this change in my local branch and wondering this would be nice addon. If others feeling this is a good addon, I can get the changes for a review and merge it eventually.