Support Micronaut 4 Context Propagation

[jjathman]

Feature description

With Micronaut 4, how context propagation works (specifically something like SFL4J's MDC) was reworked using a new API documented here. It doesn't appear as though the GCP libraries are supporting this.

For example, when using the reactive PubSub client, any logging done within a map/doOnSuccess/doOnError call does not have the MDC from the calling thread even when the context propagation is setup.

Would it be possible to support this? I'm not sure what needs to change to enable this feature.