Fix when AccessDeniedHandler is specified per RequestMatcher on
ExceptionHandlingConfigurer.
This introduces evolutions on :
- CsrfConfigurer#getDefaultAccessDeniedHandler,
to retrieve an AccessDeniedHandler similar to the one used by
ExceptionHandlingConfigurer.
- OAuth2ResourceServerConfigurer#accessDeniedHandler, to continue to
handle CsrfException with the default AccessDeniedHandler implementation
Fixes: gh-6511
4318a51971