ECS log-format doesn't comply for trace fields

[kerkhofsd]

Description

Since 3.17, Quarkus supports the ECS log-format (introduced in #43232). For example by setting following property:

quarkus.log.console.json.log-format=ecs

According to the ECS Tracing Field Details, expected fields are span.id, trace.id, ...

However AS-IS the ecs log-format still results in the nested MDC object:

... "mdc":{"spanId":"00919aa23135a7ed","parentId":"00919aa23135a7ed","traceId":"62c2815679af74499c27d6bc584b0ffb","sampled":"true"}, ...

Furthermore, I currently don't see any way possible to get the log keys compliant to the "ECS Tracing Field Details" specs.
I tried with quarkus.log.console.json.key-overrides=mdc.traceId=trace.id, which results in IllegalArgumentException: No enum constant org.jboss.logmanager.formatters.StructuredFormatter.Key.MDC.TRACEID

Implementation ideas

In case the ecs log format is configured, by default use trace field logging keys as per ECS specification.

[quarkus-bot]

/cc @brunobat (opentelemetry), @radcortez (opentelemetry)

[brunobat]

The tracing data is in the MDC context.
There needs to be an additional log formatting in the ECS side to place that data in the correct fields.

[gsmet]

@troosan any chance you could have a look?