A class with a number of handy request-based implementations of
AuthenticationManagerResolver targeted at common multi-tenancy
scenarios.
Fixes: gh-6976
Introducing OAuth2TokenIntrospectionClient and also
ReactiveOAuth2TokenIntrospectionClient as configuration points.
The DSL looks in the application context for these types in the same
way it looks for JwtDecoder and ReactiveJwtDecoder, and exposes
similar configuration methods.
Fixes: gh-6632