Remove OAuth helpers elements

[twoplustwoone]

As mentioned in #678

OAuth helper elements are now found in the api-request component, and should therefore be removed from api-console-app

[jarrodek]

I believe I made a mistake when I was putting the api-request library together. The point of using the oauth2-authorization element is to have a solution that works out-of-the-box for the API console. However, this is not suitable for all scenarios. Even in the Anypoint platform, we use events handling to proxy authorization requests as only (legacy) implicit flow can be supported this way. Other flows are blocked by CORS. When we put these components into the request editor (as it is right now) then the event is always handled by this component, regardless of handling the event elsewhere.

This should work as follows:

• only the api-console-app has included OAuth (and upcoming OIDC) authorization components
• all other components should not reference them, unless in the demo pages
• whether you are using api-console or any component it's your responsibility to include these components or handle the events

This way we remove the logic that the application doesn't use and we eliminate confusion caused by these components.

[jarrodek]

We would need to update docs as well to explain how to handle authorization.

[twoplustwoone]

Alright, I'll make the change in ApiRequest to remove the oauth components, and close this PR