Issue gh-11932, gh-9429
(Server)AuthenticationEntryPointFailureHandler should produce HTTP 500 instead
when an AuthenticationServiceException is thrown, instead of HTTP 401.
This commit deprecates the current behavior and introduces an opt-in
(Server)AuthenticationEntryPointFailureHandlerAdapter with the expected
behavior.
BearerTokenAuthenticationFilter uses the new adapter, but with a closure
to keep the current behavior re: entrypoint.
200b7fecd3