[JAVA] new Feature interface: Documentation Provider and Annotation Library (#11258)

* Implement DocumentationProviderFeatures and integrate it in AbstractJavaCodegen

* Integrate DocumentationProviderFeatures in SpringCodegen

* Run new test config spring-boot-springdoc

* Do not use Locale.ROOT

* Do not use Locale.ROOT, use NONE instead of empty list

* Revert "Do not use Locale.ROOT"

This reverts commit a0d6aac92b.

* Do not use forbidden APIs

* Fix spring maven plugin example

* Introduce DocumentationProviderFeaturesTest.java

* replace AUTO with preferredAnnotationLibrary

* remove sout.println from Test

* Apply code style.

* Update spring sample configuration to use the new property

* Update samples after merge

* fix atBean import

* Generate all samples

* Add ParameterObject to test

* Allow Subclasses to opt out

* Use OpenAPI 2 (fka Swagger RESTful API Documentation Specification) instead of just "Swagger"

* export generator docs

* Fix typo

* Fix typo - update docs.

samples/openapi3/server/petstore/springboot-reactive/src/main/java/org/openapitools/configuration/HomeController.java

@@ -1,14 +1,15 @@
 package org.openapitools.configuration;
 
+import org.springframework.context.annotation.Bean;
 import com.fasterxml.jackson.dataformat.yaml.YAMLMapper;
 import org.springframework.beans.factory.annotation.Value;
-import org.springframework.context.annotation.Bean;
 import org.springframework.core.io.Resource;
 import org.springframework.stereotype.Controller;
 import org.springframework.util.StreamUtils;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.context.annotation.Bean;
 import org.springframework.web.reactive.function.server.RouterFunction;
 import org.springframework.web.reactive.function.server.ServerResponse;