Refactor Spring Integration metrics support

Update Spring Integration metrics support since Spring Integration
`4.3.6`+ no longer needs `spring-integration-jmx` enable
`MessageChannel`, `MessageHandler` and `MessageSource` metrics.

- Add `IntegrationManagementConfiguration` conditional auto-configuration
  to provide `@EnableIntegrationManagement` when JMX is `enabled` or there
  is no `IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME` bean.
  By default this bean doesn't exist and you explicitly should declare it
  (e.g. via `@EnableIntegrationManagement`) if you would like to collect
  metrics. At the same time Spring Integration enables it when JMX
  management is present (that is a purpose of that new
  `IntegrationManagementConfiguration`)

- Change `SpringIntegrationMetricReader` to read metrics from the
  `IntegrationManagementConfigurer`, not `IntegrationMBeanExporter`

- Change `PublicMetricsAutoConfiguration` to register
  `IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME` bean if
  not present. Since we are here in `actuator`, therefore we are
  interested in the metrics for SI as well.

- Since we don't need JMX for the metrics any more, remove SI-JMX
  dependency from the `spring-boot-starter-integration`.

- Remove `IntegrationManagementConfiguration` modification from the
  `integrationMbeanExporter()`, since that looks like mutation of an
  external object, when end-user would prefer their own options.
  Therefore we don't need `ObjectProvider<IntegrationManagementConfigurer>`, too

- Add missed `MessageSourceMetrics` gathering for the
  `SpringIntegrationMetricReader`

Closes gh-7722

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/integration/IntegrationAutoConfigurationTests.java

@@ -31,6 +31,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
 import org.springframework.integration.support.channel.HeaderChannelRegistry;
+import org.springframework.integration.support.management.IntegrationManagementConfigurer;
 import org.springframework.jmx.export.MBeanExporter;
 import org.springframework.test.context.support.TestPropertySourceUtils;
 
@@ -86,12 +87,14 @@ public class IntegrationAutoConfigurationTests {
 		MBeanServer mBeanServer = this.context.getBean(MBeanServer.class);
 		assertDomains(mBeanServer, true, "org.springframework.integration",
 				"org.springframework.integration.monitor");
+		assertThat(this.context.getBean(IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME)).isNotNull();
 	}
 
 	@Test
 	public void disableJmxIntegration() {
 		load("spring.jmx.enabled=false");
 		assertThat(this.context.getBeansOfType(MBeanServer.class)).hasSize(0);
+		assertThat(this.context.getBeansOfType(IntegrationManagementConfigurer.class)).isEmpty();
 	}
 
 	@Test