* GH-8778: Fix KafkaMessageSource deadlock
Fixes https://github.com/spring-projects/spring-integration/issues/8778
The `KafkaMessageSource.doReceive()` have a lock around its whole body.
That includes the `pollRecord()` which can be blocked on the `KafkaConsumer.poll()`.
This way the rest of lifecycle management callbacks can be blocked until `KafkaConsumer.poll()` returns.
* Rework lifecycle management flags to `AtomicBoolean` since there is not too much work
in their respective callbacks
* Decrease a locking block in the `doReceive()` just to consumer setup part.
Leave `pollRecord()` outside of the lock
* Add `this.consumer.wakeup()` into `stopConsumer()` to break a `poll()` cycle
and return immediately for the next `close()` call
**Cherry-pick to `6.1.x` & `6.0.x`**
* * Use `compareAndSet` in `start` & `stop`
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