jboss-logmanager getMdcCopy() doesn't contain trace information

[ahus1]

Is your feature request related to a problem? Please describe.
The library jboss-logmanager contains since version 1.3 a new method getMdcCopy(). This one returns a map with all MDC attributes. In order to be able to log span/trace IDs for example in a JSON log, the return value should contain the values like getMdc(attribute) already supports.

Describe the solution you'd like
Extended the instrumentation to return a map that includes those attributes if they are now already set.

Describe alternatives you've considered
It would be possible to create a custom instrumentation, still I think this would be useful for everyone else as well.

Additional context

The version 1.3 has been release in Apr 2012, almost 10 years ago, and the API is available in the current versions as well.

I'll prepare a PR shortly later today.

This would allow to log the trace/span information in my setup where a Quarkus application logs JSON.
Before that change the MDC would be empty.

{"timestamp":"2022-05-28T14:33:44.197+02:00","sequence":8441,"loggerClassName":"org.jboss.logging.Logger","loggerName":"org.keycloak.events","level":"WARN","message":"type=LOGIN_ERROR, realmId=84f7eab5-4af2-40a3-ab44-783b76f5919a, c
lientId=null, userId=null, ipAddress=127.0.0.1, error=expired_code, restart_after_timeout=true, authSessionParentId=37f81c2c-2db1-4b7c-9a1c-6d0d7b2fd552, authSessionTabId=Xp6HO7eT8V4","threadName":"executor-thread-0","threadId":24,"mdc":{},"ndc":"","hostName":"tiny","processName":"QuarkusEntryPoint","processId":17268}

Now it contains the tracing information:

{"timestamp":"2022-05-28T14:33:44.197+02:00","sequence":8441,"loggerClassName":"org.jboss.logging.Logger","loggerName":"org.keycloak.events","level":"WARN","message":"type=LOGIN_ERROR, realmId=84f7eab5-4af2-40a3-ab44-783b76f5919a, clientId=null, userId=null, ipAddress=127.0.0.1, error=expired_code, restart_after_timeout=true, authSessionParentId=37f81c2c-2db1-4b7c-9a1c-6d0d7b2fd552, authSessionTabId=Xp6HO7eT8V4","threadName":"executor-thread-0","threadId":24,"mdc":{"trace_flags":"aa4a99929037cee4a35fb8666b924c04","trace_id":"aa4a99929037cee4a35fb8666b924c04","span_id":"aa4a99929037cee4a35fb8666b924c04"},"ndc":"","hostName":"tiny","processName":"QuarkusEntryPoint","processId":17268}