Introduce Spring Modulith Actuator module to expose the application module structure as Spring Boot actuator. This required a Spring Modulith Runtime module to be extracted from the Spring Modulith Observability one. The former now contains the auto-configured ApplicationRuntime and ApplicationModulesRuntime bean instances to be able to bootstrap a ApplicationModules asynchronously on application startup. The actuator module then contains a Spring Boot @Endpoint implementation consuming the ApplicationModules to render JSON describing the application module structure.
Overhauled the module canvas in various ways. By default, we now skip "empty" rows. In other words, if we do not find any published events for example, we skip the entire row. CanvasOptions.revealEmptyRows() can be used to keep those empty rows around. We now also expose all value types and Spring bean references.
Refactored the dependency lookup APIs on ApplicationModule. Both DependencyType and DependencyDepth are now top-level types. Also, ApplicationModuleDependency and ApplicationModuleDependencies were introduced as explicit types. In the course of that, ApplicationModule.getDependencies(…) has got its return type changed from List<ApplicationModule> to ApplicationModuleDependencies. The internal ModuleDependency type has been renamed to QualifiedDependency.
Upgrade to Spring Boot 3 and Java 17 as project baselines. Removed legacy JavaEE modules and replaced them by ones compatible with JakartaEE 9.
Disabled the Observability module for now as Spring Cloud Sleuth has been removed the Boot 3 compatible Spring Cloud branch and we need to migrate the module to Micrometer first.
