Include content validation decision in describe output

After hitting a build failure (NEXUS-8793), Stuart McCulloch, Tamás Cservenák and I think it'd be beneficial for troubleshooting Content Validation issues to have a line in the describe output relaying the decisions made.

This will make it easier to troubleshoot issues like NEXUS-8763.

Currently there's nothing in there nor is there anything at default log levels, making it somewhat of a ghost.

I did not review NX2 to see what it does.