Made changes to the way pages are viewed for registered/new/logged_out user other than redirecting appropriately after role selection

Issue Fix

Fixes #25

Screenshots

Really no UI added. It was a functionality.

Description

I have made the following changes 👍

1. After the user registers, he gets redirected to either the doctor or patient homepage based on his role
2. If a logged-in user closes and opens the app anytime, later on, his details are stored and the same will enable us to directly take him to his dashboard as per his role
3. If a user logs-out, on the next login via OTP, he won't be asked his details or role, because the user already exists

Reviewers

@ajitesh13 @dotrachit Kindly review and merge!