Deprecate CookieGenerator

This commit deprecates CookieGenerator in favor of the more modern
alternative, ResponseCookie.

See gh-28870

spring-webmvc/src/main/java/org/springframework/web/servlet/i18n/CookieLocaleResolver.java

@@ -59,6 +59,7 @@ import org.springframework.web.util.WebUtils;
  * @see #setDefaultLocale
  * @see #setDefaultTimeZone
  */
+@SuppressWarnings("deprecation")
 public class CookieLocaleResolver extends AbstractLocaleContextResolver {
 
 	/**