GH-87 - Expose module structure as actuator endpoint.

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.

spring-modulith-observability/src/test/java/org/springframework/modulith/observability/autoconfigure/SpringBootApplicationRuntimeUnitTests.java

@@ -1,49 +0,0 @@
-/*
- * Copyright 2022 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.modulith.observability.autoconfigure;
-
-import static org.assertj.core.api.Assertions.*;
-
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
-import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
-import org.springframework.aop.framework.ProxyFactory;
-import org.springframework.context.ApplicationContext;
-import org.springframework.modulith.observability.ApplicationRuntime;
-
-/**
- * Unit tests for {@link SpringBootApplicationRuntime}.
- *
- * @author Oliver Drotbohm
- */
-@ExtendWith(MockitoExtension.class)
-public class SpringBootApplicationRuntimeUnitTests {
-
-	@Mock ApplicationContext context;
-
-	@Test
-	void extractsUserTypeFromClassBasedProxy() {
-
-		Object proxy = new ProxyFactory(new Sample()).getProxy();
-		ApplicationRuntime runtime = new SpringBootApplicationRuntime(context);
-
-		assertThat(proxy.getClass()).isNotEqualTo(Sample.class);
-		assertThat(runtime.getUserClass(proxy, "sample")).isEqualTo(Sample.class);
-	}
-
-	static class Sample {}
-}