Please consider making OAuth2ClientFeature a public class

We have a use case where there is an OAuth2 request back end to back end, with no user interaction possible, so that it appears OAuth2CodeGrantFlow is not a possible solution as this flow expects user interaction, The user has already generated an Access Token and Refresh Token using OAuth2CodeGrantFlow that is stored in a database.

We wish to use the OAuth2ClientFeature as follows
Feature feature = new OAuth2ClientFeature();
client.register(feature);

However this is not possible as the class is package private. Also this would not handle the case that the AccessToken has expired.

Please confirm if this is a valid use case, or is there another way to accomplish what we want.
#### Affected Versions
[2.23.2]