Migrate native hints for Integation Graph types from Spring Boot #3994
Description
Right now the hints for Graph and its node types are exposed in the IntegrationGraphEndpoint of Spring Boot Actuator.
This makes it working only of such a feature is enabled in Spring Boot, however the IntegrationGraphServer is Spring Integration feature and can be used even without Spring Boot.
It feels more natural to support native hints for Integation Graph directly in Spring Integration.
So, migrate those hints back to Spring Integration as it was before with experimental Spring Native project.