OpenID -- Add Implementation of Authorization Code Flow

Currently the openid implementation only implements the Implicit Flow which is not regarded as industry standard anymore.

Reference: https://auth0.com/docs/flows/authorization-code-flow

This ticket is to expand the current implementation to allow the following features:

1. Configuration parameters to enable Authorization Code Flow (Still want to have Implicit Flow support)
2. Add front-end support for Authorization Code Flow using open source libraries that are approved implementations of what we need.  I.e. oidc-client-js

I have been unable to find direct AngularJS modules that would solve this issue, but I will keep looking.