* INT-4397: Fix headers filtering for @Transformer
JIRA: https://jira.spring.io/browse/INT-4397
The `AbstractMessageProcessingTransformer` doesn't honor a configured
`notPropagatedHeaders` and copies all the request headers to the
message to return
* Add `setNotPropagatedHeaders()` into the `AbstractMessageProcessingTransformer`
and implement there a logic to filter headers, similar to what we have
in the `AbstractMessageProducingHandler`
* Overrider `updateNotPropagatedHeaders()` in the `MessageTransformingHandler`
to propagate `notPropagatedHeaders` to the `AbstractMessageProcessingTransformer`
delegate
* * Revert `final` for the `AbstractMessageProducingHandler.updateNotPropagatedHeaders()`
* Override `addNotPropagatedHeaders()` for the `MessageTransformingHandler()`
and populate `notPropagatedHeaders` into the target `AbstractMessageProcessingTransformer`
from there
* Also populate `notPropagatedHeaders` from the `AbstractMessageProcessingTransformer.doInit()`
* Implement a `AbstractIntegrationMessageBuilder.filterAndCopyHeadersIfAbsent()`
for a general logic to filter `notPropagatedHeaders` and copy the result
headers set into the target message if they are absent
* Use an new `filterAndCopyHeadersIfAbsent()` in the `AbstractMessageProducingHandler`
and `AbstractMessageProcessingTransformer`to avoid code block duplication
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