1. Created new WebFilter AnonymousAuthenticationWebFilter to
for anonymous authentication
2. Created class AnonymousSpec, method anonymous to configure
anonymous authentication in ServerHttpSecurity
3. Added ANONYMOUS_AUTHENTICATION order after AUTHENTICATION for
anonymous authentication in SecurityWebFiltersOrder
4. Added tests for anonymous authentication in
AnonymousAuthenticationWebFilterTests and ServerHttpSecurityTests
5. Added support for Controller in WebTestClientBuilder
Fixes: gh-5934
2b369cfe98