Fixes: #9442
Issue link: https://github.com/spring-projects/spring-integration/issues/9442
When we register a `BeanDefinition`, its metadata is cached in the `DefaultListableBeanFactory.mergedBeanDefinitionHolders`
and it is not removed when we destroy bean.
This causes a memory leak with dynamic integration flows where even we destroy beans, their metadata is still cached.
This has more serious impact when random ids are used for dynamic integration flows.
* Rework `IntegrationFlowContext` logic to register singletons instead of `BeanDefinition`
* Adjust `IntegrationFlowBeanPostProcessor` logic to register singletons or `BeanDefinition`
according to the presence of `BeanDefinition` of the `IntegrationFlow` we are processing
* Introduce `ComponentSourceAware` to mimic a `BeanDefinition` metadata logic for bean source and its description.
This info helps a lot with exceptions where class in the `IntegrationFlow` might be fully from a Spring Integration package.
So, to give a clue what end-user code is related to the exception,
such a `ComponentSourceAware` is there to preserver and transfer "bean source"
* Implement `ComponentSourceAware` in the `IntegrationObjectSupport` since this is a central
place where we generate info for the Spring Integration exceptions
* Implement `ComponentSourceAware` in the `StandardIntegrationFlow` to propagate bean source info
down to its components for the mentioned `IntegrationObjectSupport` logic
* Introduce inner `StandardIntegrationFlowContext.IntegrationFlowComponentSourceAwareAdapter`
to be able to transfer "bean source" info from builder down to the target `IntegrationFlow` bean
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