Support for oauth2 passport strategies, missing provisions for redirect and callback #4902
Description
Suggestion
The StrategyAdapter is not adding the redirect() method in passport strategies, required for Oauth2 authorization flows.
This would also need some handling on the invocation side, i.e the Sequence class and others might need to participate according to the oauth flow.
Use Cases
login thru third party apps like facebook, google
#3958
Acceptance criteria
- - strategy adapter must add all necessary calls for oauth2 in passport strategies
- - unit tests with mock redirect and mock third party app
- - must satisfy How to migrate apps using loopback-component-passport #3958 for login with third party apps