Improve the implementation that handles non-SMP traffic on the serial transport #12
Description
This PR added "support" for Zephyr sending log messages in between SMP packets: 31717db
The implementation and testing was rushed and of low quality, in my opinion.
Further, I do not like that messages from Zephyr are logged. I feel that they should be returned to the caller and the caller decides what to do with them. The problem is that it is only the SMP Shell Transport that has this issue. One way to handle it would simply be to fill an asyncio queue with the logs (non SMP messages) and then the caller can simply choose whether or not to clear the queue.