Refresh token if the existing token in the db is expired

[yatharthranjan]

We need to add handling of 2 extra cases for Management portal Authorizer-

1. When the stored Access token in db is expired, use the refresh token to get a new access token. I think this is already present but double check.
2. If the refresh token is also expired, read the meta-token from the config to get a new one. If the meta-token is also not valid, show an error to the user to add a new meta-token from management portal and exit the application.