[java-spring] - 22859 - spring http interface library must support use bean validation

[Picazsoo]

Spring declares that Http Interface annotations can also be used server-side for controller instantiation: https://docs.spring.io/spring-framework/reference/integration/rest-clients.html#rest-http-service-client

On the server side, an @controller class can implement the same interface to handle requests with @HttpExchange controller methods. In such case it makes sense to allow the bean validation option and thus annotate both the model and the api methods with jakarta.validation annotations.

I will add some unit tests in the coming days.

closes #22859

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Summary by cubic

Add Bean Validation support to the Spring HTTP Interface library (reactive and non‑reactive). The generator now respects useBeanValidation and performBeanValidation (both default to false). Fixes #22859.

• New Features
  • Respect useBeanValidation and performBeanValidation in SpringCodegen for spring-http-interface, defaulting both to false when not set.
  • Generate @validated on interfaces when Bean Validation is enabled and Spring built-in validation is not used; add required validation imports.
  • Add sample configs for bean-validation variants and update CI to build them.

^{Written for commit b9cb91e. Summary will update on new commits.}